Development of a Cl-impregnated activated carbon for entrained-flow capture of elemental mercury.

Science.gov (United States)

Ghorishi, S Behrooz; Keeney, Robert M; Serre, Shannon D; Gullett, Brian K; Jozewicz, Wojciech S

2002-10-15

Efforts to discern the role of an activated carbon's surface functional groups on the adsorption of elemental mercury (Hg0) and mercuric chloride demonstrated that chlorine (Cl) impregnation of a virgin activated carbon using dilute solutions of hydrogen chloride leads to increases (by a factor of 2-3) in fixed-bed capture of these mercury species. A commercially available activated carbon (DARCO FGD, NORITAmericas Inc. [FGD])was Cl-impregnated (Cl-FGD) [5 lb (2.3 kg) per batch] and tested for entrained-flow, short-time-scale capture of Hg0. In an entrained flow reactor, the Cl-FGD was introduced in Hg0-laden flue gases (86 ppb of Hg0) of varied compositions with gas/solid contact times of about 3-4 s, resulting in significant Hg0 removal (80-90%), compared to virgin FGD (10-15%). These levels of Hg0 removal were observed across a wide range of very low carbon-to-mercury weight ratios (1000-5000). Variation of the natural gas combustion flue gas composition, by doping with nitrogen oxides and sulfur dioxide, and the flow reactor temperature (100-200 degrees C) had minimal effects on Hg0 removal bythe Cl-FGD in these carbon-to-mercury weight ratios. These results demonstrate significant enhancement of activated carbon reactivity with minimal treatment and are applicable to combustion facilities equipped with downstream particulate matter removal such as an electrostatic precipitator.

Removal of hydrogen sulfide and sulfur dioxide by carbons impregnated with triethylenediamine.

Science.gov (United States)

Wu, Li-Chun; Chang, Tsu-Hua; Chung, Ying-Chien

2007-12-01

Activated carbon (AC) adsorption has long been considered to be a readily available technology for providing protection against exposure to acutely toxic gases. However, ACs without chemical impregnation have proven to be much less efficient than impregnated ACs in terms of gas removal. The impregnated ACs in current use are usually modified with metalloid impregnation agents (ASC-carbons; copper, chromium, or silver) to simultaneously enhance the chemical and physical properties of the ACs in removing specific poisonous gases. These metalloid agents, however, can cause acute poisoning to both humans and the environment, thereby necessitating the search for organic impregnation agents that present a much lower risk. The aim of the study reported here was to assess AC or ASC-carbon impregnated with triethylenediamine (TEDA) in terms of its adsorption capability for simulated hydrogen sulfide (H2S) and sulfur dioxide (SO2) gases. The investigation was undergone in a properly designed laboratory-scale and industrial fume hood evaluation. Using the system reported here, we obtained a significant adsorption: the removal capability for H2S and SO2 was 375 and 229 mg/g-C, respectively. BET measurements, element analysis, scanning electron microscopy, and energy dispersive spectrometry identified the removal mechanism for TEDA-impregnated AC to be both chemical and physical adsorption. Chemical adsorption and oxidation were the primary means by which TEDA-impregnated ASC-carbons removed the simulated gases.

Thermal Effect on the phosphoric Acid Impregnated Activated Carbon Fiber and Adsorption Properties Toward Isoprene

Energy Technology Data Exchange (ETDEWEB)

Hwang, Taek Sung; Lee, Jin Hyok; Kang, Kyung suk [Department of Chemical Engineering, College of Engineering, Chungnam National University, Taejon (Korea); Kim, Kwang Young [Ace Lab. Co. Ltd. Taejon (Korea); Rhee, Moon Soo [Korea Ginseng and Tobacoo Research Institute, Taejon (Korea)

2001-05-01

To introduce chemisorption property and improve adsorption capacities for isoprene, ACF (Activated Carbon Fiber) was impregnated by phosphoric acid. As the impregnated ACF was dried by programmed temperature from 300 degree C to 500 degree C, degree of impregnation, surface area, thermal stability and adsorption properties for isoprene were observed. The degree of impregnation of the ACF, dried at the 400 degree C, was 12.7 w/w% and surface area was 1148 m{sup 2}/g. Over the temperature range of 450 degree C to 700 degree C, there was one-step thermal degradation by the thermal decomposition of phosphonyl group. The adsorption rate of phosphoric acid on the impregnated ACF, which was dried at 400 degree C, was the fastest. The breakthrough time of ACF that was dried at 400 degree C was 18 min., and its adsorption capacity improved roughly 7.2 times in comparison to the pure ACF. In addition, it was observed the adsorption properties persisted even after the regeneration. The adsorption efficiency of regenerated ACF was 66 percent compared to the unused impregnated ACF. 21 refs., 7 figs., 3 tabs.

Effect of halide impregnation on elemental mercury removal of activated carbons

Energy Technology Data Exchange (ETDEWEB)

Yim, Yoon Ji; Park, Soo Jin [Dept. of Chemistry, Inha University, Incheon (Korea, Republic of)

2017-02-15

Activated carbons (ACs) were impregnated with potassium halides (KX) to enhance the removal efficiency of elemental mercury (Hg{sup 0}). In this work, the impregnation effect of potassium bromide (KBr) and potassium iodine (KI) were investigated. The surface properties of KX-ACs were determined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The pore structures and total pore volumes of the KX-ACs were analyzed using the N{sub 2} /77 K adsorption isotherms. The Hg{sup 0} removal efficiency of KBr-ACs and KI-ACs was studied under simulated flue gas conditions. The effects of KI and KBr loading, adsorption temperature, and flue gas components on Hg{sup 0} removal efficiency were also investigated. The results showed that the Hg{sup 0} removal efficiency of the ACs was significantly enhanced by KI or KBr impregnation, and KI-ACs showed higher Hg{sup 0} removal efficiency than KBr-ACs under the same conditions. An increase in KI or KBr loading and higher adsorption temperatures improved the Hg{sup 0} removal efficiency, indicating that chemisorption occurred due to the reaction between X− and Hg{sup 0}. The lower extent of Hg{sup 0} removal exhibited by the KBr-ACs than by the KI-ACs was due to the difficulty of Br{sub 2} formation on the surfaces.

CO{sub 2} capture using fly ash-derived activated carbons impregnated with low molecular mass amines

Energy Technology Data Exchange (ETDEWEB)

Karl M. Smith; Ana Arenillas; Trevor C. Drage; Colin E. Snape [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

2005-07-01

At the Nottingham Fuel and Energy centre, a program is underway to develop high capacity CO{sub 2} sorbents for flue gas from large point sources such as fossil-fuel power plants. Two different approaches are presented here. Firstly, the modification of the surface chemistry of low cost carbos by impregnation with a basic nitrogen-containing polymer and different amines is described. Secondly, the development of high nitrogen content carbon matrix adsorbents by carbonization and subsequent thermal or chemical activation of a range of materials is summarised. Such high nitrogen content adsorbents, generated at high temperature, are advantageous as their inherent thermal stability will minimise alteration during multiple adsorption and regeneration cycles. Relatively low MM amines, namely diethanolamine and (DEA, MM 105) and tetraethylenepentaamineacrylonitrile (TEPAN, MM 311) are used to produce high capacity CO{sub 2} sorbents from activated carbons derived form unburned carbon in fly ash, which have low mesoporosities. The unburned carbons were obtained through the froth flotation and dry-sieving of fly ash and their activation was performed using, variously, steam and CO{sub 2}. It was found that the impregnation of a fly-ash derived carbon with amines can produce CO{sub 2} sorbents, with uptakes up to 5 wt% at 75{degree}C. Nitrogen incorporation in carbon materials generally promotes the adsorption of CO{sub 2} with the process being totally reversible but, although the amount of nitrogen incorporated into the adsorbent is important, nitrogen functionality is also important. 9 refs., 2 figs.

Granular activated carbon with grafted nanoporous polymer enhances nanoscale zero-valent iron impregnation and water contaminant removal

DEFF Research Database (Denmark)

Mines, Paul D.; Uthuppu, Basil; Thirion, Damien

2018-01-01

Granular activated carbon was customized with a chemical grafting procedure of a nanoporous polymeric network for the purpose of nanoscale zero-valent iron impregnation and subsequent water contaminant remediation. Characterization of the prepared composite material revealed that not only was the...

Destruction of Toluene by the Combination of High Frequency Discharge Electrodeless Lamp and Manganese Oxide-Impregnated Granular Activated Carbon Catalyst

Directory of Open Access Journals (Sweden)

Jianhui Xu

2014-01-01

Full Text Available The destruction of low concentration of toluene (0–30 ppm has been studied under the UV/photogenerated O3/MnO2-impregnated granular activated carbon (MnO2-impregnated GAC process by the combination of self-made high frequency discharge electrodeless lamp (HFDEL with MnO2-impregnated GAC catalyst. Experimental results showed that the initial toluene concentration can strongly affect the concentration of photogenerated O3 from HFDEL and the efficiency and mass rate of destruction of toluene via HFDEL/MnO2-impregnated GAC system. Active oxygen and hydroxyl radicals generated from HFDEL/MnO2-impregnated GAC system played a key role in the decomposition of toluene process and the intermediates formed by photolysis are more prone to be mineralized by the subsequent MnO2-impregnated GAC catalyst compared to the original toluene, resulting in synergistic mineralization of toluene by HFDEL/MnO2-impregnated GAC system. The role of MnO2-impregnated GAC catalyst is not only to eliminate the residual O3 completely but also to enhance the decomposition and mineralization of toluene.

On the reactive adsorption of ammonia on activated carbons modified by impregnation with inorganic compounds

Energy Technology Data Exchange (ETDEWEB)

Bandosz, T.J.; Petit, C. [CUNY City College, New York, NY (United States). Dept. of Chemistry

2009-10-15

Ammonia adsorption was studied under dynamic conditions, at room temperature, on activated carbons of different origins (coal-based, wood-based and coconut-shell-based carbons) before and after their impregnation with various inorganic compounds including metal chlorides, metal oxides and polycations. The role of humidity was evaluated by running tests in both dry and moist conditions. Adsorbents were analyzed before and after exposure to ammonia by thermal analyses, sorption of nitrogen, potentiometric titration, X-ray diffraction and FTIR spectroscopy. Results of breakthrough tests show significant differences in terms of adsorption capacity depending on the parent carbon, the impregnates and the experimental conditions. It is found that surface chemistry governs ammonia adsorption on the impregnated carbons. More precisely, it was demonstrated that a proper combination of the surface pH, the strength, type and amount of functional groups present on the adsorbents' surface is a key point in ammonia uptake. Water can have either positive or negative effects on the performance of adsorbents. It can enhance NH{sub 3} adsorption capacity since it favors ammonia dissolution and thus enables reaction between ammonium ions and carboxylic groups from the carbons' surface. On the other hand, water can also reduce the performance from the strength of adsorption standpoint. It promotes dissolution of ammonia and that ammonia is first removed from the system when the adsorbent bed is purged with air. Ammonia, besides adsorption by van der Waals forces and dissolution in water, is also retained on the surface via reactive mechanisms such as acid-base reactions (Bronsted and Lewis) or complexation. Depending on the materials used and the experimental conditions, 6-47% ammonia adsorbed is strongly retained on the surface even when the bed is purged with air.

Carbonization of heavy metal impregnated sewage sludge oriented towards potential co-disposal

Energy Technology Data Exchange (ETDEWEB)

Dou, Xiaomin [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 201804 (China); Chen, Dezhen, E-mail: chendezhen@tongji.edu.cn [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 201804 (China); Hu, Yuyan; Feng, Yuheng [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 201804 (China); Dai, Xiaohu [National Engineering Research Centre for Urban Pollution Control, Tongji University, Shanghai 200092 (China); College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

2017-01-05

Highlights: • The carbonization of SS with externally impregnated heavy metals was investigated. • Externally impregnated heavy metals can be immobilized in the SSC. • Higher carbonization temperature help produce non-hazardous SSC. • Incineration FA can be kneaded into SS for co-disposal through co-carbonization. - Abstract: Sewage sludge (SS) is adopted as a stabilizer to immobilize externally impregnated heavy metals through carbonization oriented towards the co-disposal of SS and some hazardous wastes. Firstly Cu and Pb were impregnated into SS to ascertain the impregnating capacity and leaching behaviours of heavy metals in the resulting sewage sludge char (SSC). Meanwhile, scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to detect the heavy metal phase in the SSC. The results showed that within 400–800 °C and an impregnating concentration ≨0.5 wt%, more than 90% of the externally impregnated Cu and Pb were remained in the SSC and immobilized. And higher temperatures helped produce non-hazardous SSC. In addition, SEM and XRD analyses revealed that externally impregnated heavy metals could be converted into stable forms and evenly distributed throughout the SSC. In the second step municipal solid waste incineration fly ash (FA) was kneaded into SS and subjected to carbonization; it has been proved that the heavy metals in FA can be well immobilized in the resulting char when FA: SS mass ratio is 1:5. Those results show that sewage sludge can be co-carbonized with wastes contaminated with heavy metals to achieve co-disposal.

Carbonization of heavy metal impregnated sewage sludge oriented towards potential co-disposal

International Nuclear Information System (INIS)

Dou, Xiaomin; Chen, Dezhen; Hu, Yuyan; Feng, Yuheng; Dai, Xiaohu

2017-01-01

Highlights: • The carbonization of SS with externally impregnated heavy metals was investigated. • Externally impregnated heavy metals can be immobilized in the SSC. • Higher carbonization temperature help produce non-hazardous SSC. • Incineration FA can be kneaded into SS for co-disposal through co-carbonization. - Abstract: Sewage sludge (SS) is adopted as a stabilizer to immobilize externally impregnated heavy metals through carbonization oriented towards the co-disposal of SS and some hazardous wastes. Firstly Cu and Pb were impregnated into SS to ascertain the impregnating capacity and leaching behaviours of heavy metals in the resulting sewage sludge char (SSC). Meanwhile, scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to detect the heavy metal phase in the SSC. The results showed that within 400–800 °C and an impregnating concentration ≨0.5 wt%, more than 90% of the externally impregnated Cu and Pb were remained in the SSC and immobilized. And higher temperatures helped produce non-hazardous SSC. In addition, SEM and XRD analyses revealed that externally impregnated heavy metals could be converted into stable forms and evenly distributed throughout the SSC. In the second step municipal solid waste incineration fly ash (FA) was kneaded into SS and subjected to carbonization; it has been proved that the heavy metals in FA can be well immobilized in the resulting char when FA: SS mass ratio is 1:5. Those results show that sewage sludge can be co-carbonized with wastes contaminated with heavy metals to achieve co-disposal.

Adsorption/desorption of low concentration of carbonyl sulfide by impregnated activated carbon under micro-oxygen conditions

International Nuclear Information System (INIS)

Wang, Xueqian; Qiu, Juan; Ning, Ping; Ren, Xiaoguang; Li, Ziyan; Yin, Zaifei; Chen, Wei; Liu, Wei

2012-01-01

Highlights: ► Carbonyl sulfide can be catalytic oxidized by micro-oxygen in the off-gas. ► How to use the trace oxygen for the oxidation of carbonyl sulfide was a challenge. ► The SO 4 2− species in the adsorbent sample were generated by a catalytic oxidation process. - Abstract: Activated carbon modified with different impregnants has been studied for COS removal efficiency under micro-oxygen conditions. Activated carbon modified with Cu(NO 3 ) 2 –CoPcS–KOH (denoted as Cu–Co–KW) is found to have markedly enhanced adsorption purification ability. In the adsorption purification process, the reaction temperature, oxygen concentration, and relative humidity of the gas are determined to be three crucial factors. A breakthrough of 43.34 mg COS/g adsorbent at 60 °S and 30% relative humidity with 1.0% oxygen is shown in Cu–Co–KW for removing COS. The structures of the activated carbon samples are characterized using nitrogen adsorption, and their surface chemical structures are analyzed with X-ray photoelectron spectroscopy (XPS). Modification of Cu(NO 3 ) 2 –CoPcS–KOH appears to improve the COS removal capacity significantly, during which, SO 4 2− is presumably formed, strongly adsorbed, and present in the micropores ranging from 0.7 to 1.5 nm. TPD is used to identify the products containing sulfur species on the carbon surface, where SO 2 and COS are detected in the effluent gas generated from exhausted Cu–Co–KW (denoted Cu–Co–KWE). According to the current study results, the activated carbon impregnated with Cu(NO 3 ) 2 –CoPcS–KOH promises a good candidate for COS adsorbent, with the purified gas meeting requirements for desirable chemical feed stocks.

Adsorption/desorption of low concentration of carbonyl sulfide by impregnated activated carbon under micro-oxygen conditions

Energy Technology Data Exchange (ETDEWEB)

Wang, Xueqian, E-mail: wxqian3000@yahoo.com.cn [Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Qiu, Juan; Ning, Ping; Ren, Xiaoguang; Li, Ziyan; Yin, Zaifei; Chen, Wei; Liu, Wei [Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China)

2012-08-30

Highlights: Black-Right-Pointing-Pointer Carbonyl sulfide can be catalytic oxidized by micro-oxygen in the off-gas. Black-Right-Pointing-Pointer How to use the trace oxygen for the oxidation of carbonyl sulfide was a challenge. Black-Right-Pointing-Pointer The SO{sub 4}{sup 2-} species in the adsorbent sample were generated by a catalytic oxidation process. - Abstract: Activated carbon modified with different impregnants has been studied for COS removal efficiency under micro-oxygen conditions. Activated carbon modified with Cu(NO{sub 3}){sub 2}-CoPcS-KOH (denoted as Cu-Co-KW) is found to have markedly enhanced adsorption purification ability. In the adsorption purification process, the reaction temperature, oxygen concentration, and relative humidity of the gas are determined to be three crucial factors. A breakthrough of 43.34 mg COS/g adsorbent at 60 Degree-Sign S and 30% relative humidity with 1.0% oxygen is shown in Cu-Co-KW for removing COS. The structures of the activated carbon samples are characterized using nitrogen adsorption, and their surface chemical structures are analyzed with X-ray photoelectron spectroscopy (XPS). Modification of Cu(NO{sub 3}){sub 2}-CoPcS-KOH appears to improve the COS removal capacity significantly, during which, SO{sub 4}{sup 2-} is presumably formed, strongly adsorbed, and present in the micropores ranging from 0.7 to 1.5 nm. TPD is used to identify the products containing sulfur species on the carbon surface, where SO{sub 2} and COS are detected in the effluent gas generated from exhausted Cu-Co-KW (denoted Cu-Co-KWE). According to the current study results, the activated carbon impregnated with Cu(NO{sub 3}){sub 2}-CoPcS-KOH promises a good candidate for COS adsorbent, with the purified gas meeting requirements for desirable chemical feed stocks.

Heavy metal ion adsorption onto polypyrrole-impregnated porous carbon.

Science.gov (United States)

Choi, Moonjung; Jang, Jyongsik

2008-09-01

Polypyrrole-impregnated porous carbon was readily synthesized using vapor infiltration polymerization of pyrrole monomers. The results show that the functionalized polymer layer was successfully coated onto the pore surface of carbon without collapse of mesoporous structure. The modified porous carbon exhibited an improved complexation affinity for heavy metal ions such as mercury, lead, and silver ions due to the amine group of polypyrrole. The introduced polypyrrole layer could provide the surface modification to be applied for heavy metal ion adsorbents. Especially, polymer-impregnated porous carbon has an enhanced heavy metal ion uptake, which is 20 times higher than that of adsorbents with amine functional groups. Furthermore, the relationship between the coated polymer amount and surface area was also investigated in regard to adsorption capacity.

The effect of carbon type on arsenic and trichloroethylene removal capabilities of iron (hydr)oxide nanoparticle-impregnated granulated activated carbons

Energy Technology Data Exchange (ETDEWEB)

Cooper, Anne Marie, E-mail: Anne.M.Cooper@asu.edu [Environmental Technology, College of Technology and Innovation. Arizona State University - Polytechnic Campus, 6075 South Williams Campus Loop West, Mesa, AZ 85212 (United States); Hristovski, Kiril D., E-mail: Kiril.Hristovski@asu.edu [Environmental Technology, College of Technology and Innovation, Arizona State University - Polytechnic Campus, 6073 South Backus Mall, Mesa, AZ 85212 (United States); Moeller, Teresia, E-mail: tmoller@solmetex.com [SolmeteX - Division of Layne Christiansen, 50 Bearfoot Road, Northborough, MA 01532 (United States); Westerhoff, Paul, E-mail: p.westerhoff@asu.edu [School of Sustainable Engineering and the Built Environment, Arizona State University, Box 5306, Tempe, AZ 85287-5306 (United States); Sylvester, Paul, E-mail: psylvester@solmetex.com [SolmeteX - Division of Layne Christiansen, 50 Bearfoot Road, Northborough, MA 01532 (United States)

2010-11-15

This study investigates the impact of the type of virgin granular activated carbon (GAC) media used to synthesize iron (hydr)oxide nanoparticle-impregnated granular activated carbon (Fe-GAC) on its properties and its ability to remove arsenate and organic trichloroethylene (TCE) from water. Two Fe-GAC media were synthesized via a permanganate/ferrous ion synthesis method using bituminous and lignite-based virgin GAC. Data obtained from an array of characterization techniques (pore size distribution, surface charge, etc.) in correlation with batch equilibrium tests, and continuous flow modeling suggested that GAC type and pore size distribution control the iron (nanoparticle) contents, Fe-GAC synthesis mechanisms, and contaminant removal performances. Pore surface diffusion model calculations predicted that lignite Fe-GAC could remove {approx}6.3 L g{sup -1} dry media and {approx}4 L g{sup -1} dry media of water contaminated with 30 {mu}g L{sup -1} TCE and arsenic, respectively. In contrast, the bituminous Fe-GAC could remove only {approx}0.2 L/g dry media for TCE and {approx}2.8 L/g dry media for As of the same contaminated water. The results show that arsenic removal capability is increased while TCE removal is decreased as a result of Fe nanoparticle impregnation. This tradeoff is related to several factors, of which changes in surface properties and pore size distributions appeared to be the most dominant.

The effect of carbon type on arsenic and trichloroethylene removal capabilities of iron (hydr)oxide nanoparticle-impregnated granulated activated carbons

International Nuclear Information System (INIS)

Cooper, Anne Marie; Hristovski, Kiril D.; Moeller, Teresia; Westerhoff, Paul; Sylvester, Paul

2010-01-01

This study investigates the impact of the type of virgin granular activated carbon (GAC) media used to synthesize iron (hydr)oxide nanoparticle-impregnated granular activated carbon (Fe-GAC) on its properties and its ability to remove arsenate and organic trichloroethylene (TCE) from water. Two Fe-GAC media were synthesized via a permanganate/ferrous ion synthesis method using bituminous and lignite-based virgin GAC. Data obtained from an array of characterization techniques (pore size distribution, surface charge, etc.) in correlation with batch equilibrium tests, and continuous flow modeling suggested that GAC type and pore size distribution control the iron (nanoparticle) contents, Fe-GAC synthesis mechanisms, and contaminant removal performances. Pore surface diffusion model calculations predicted that lignite Fe-GAC could remove ∼6.3 L g -1 dry media and ∼4 L g -1 dry media of water contaminated with 30 μg L -1 TCE and arsenic, respectively. In contrast, the bituminous Fe-GAC could remove only ∼0.2 L/g dry media for TCE and ∼2.8 L/g dry media for As of the same contaminated water. The results show that arsenic removal capability is increased while TCE removal is decreased as a result of Fe nanoparticle impregnation. This tradeoff is related to several factors, of which changes in surface properties and pore size distributions appeared to be the most dominant.

Unmodified versus caustics-impregnated carbons for control of hydrogen sulfide emissions from sewage treatment plants

Energy Technology Data Exchange (ETDEWEB)

Bandosz, T.J.; Bagreev, A.; Adib, F.; Turk, A.

2000-03-15

Unmodified and caustic-impregnated carbons were compared as adsorbents for hydrogen sulfide in the North River Water Pollution Control Plant in New York City over a period of 2 years. The carbons were characterized using accelerated H{sub 2}S breakthrough capacity tests, sorption of nitrogen, potentiometric titration, and thermal analysis. The accelerated laboratory tests indicate that the initial capacity of caustic-impregnated carbons exceeds that of unmodified carbon, but the nature of real-life challenge streams, particularly their lower H{sub 2}S concentrations, nullifies this advantage. As the caustic content of the impregnated carbon is consumed, the situation reverses, and the unmodified carbon becomes more effective. When the concentration of H{sub 2}S is low, the developed surface area and pore volume along with the affinity to retain water create a favorable environment for dissociative adsorption of hydrogen sulfide and its oxidation to elemental sulfur, S{sup 4+}, and S{sup 6+}. In the case of the caustic carbon, the catalytic impact of the carbon surface is limited, and its good performance lasts only while active base is present. The results also show the significant differences in performance of unmodified carbons due to combined effects of their porosity and surface chemistry.

Adsorption and oxidation of SO₂in a fixed-bed reactor using activated carbon produced from oxytetracycline bacterial residue and impregnated with copper.

Science.gov (United States)

Zhou, Baohua; Yu, Lei; Song, Hanning; Li, Yaqi; Zhang, Peng; Guo, Bin; Duan, Erhong

2015-02-01

The SO₂removal ability (including adsorption and oxidation ability) of activated carbon produced from oxytetracycline bacterial residue and impregnated with copper was investigated. The activated carbon produced from oxytetracycline bacterial residue and modified with copper was characterized by x-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The effects of the catalysts, SO₂concentration, weight hourly space velocity, and temperature on the SO₂adsorption and oxidation activity were evaluated. Activated carbon produced from oxytetracycline bacterial residue and used as catalyst supports for copper oxide catalysts provided high catalytic activity for the adsorbing and oxidizing of SO₂from flue gases.

Carbonization of heavy metal impregnated sewage sludge oriented towards potential co-disposal.

Science.gov (United States)

Dou, Xiaomin; Chen, Dezhen; Hu, Yuyan; Feng, Yuheng; Dai, Xiaohu

2017-01-05

Sewage sludge (SS) is adopted as a stabilizer to immobilize externally impregnated heavy metals through carbonization oriented towards the co-disposal of SS and some hazardous wastes. Firstly Cu and Pb were impregnated into SS to ascertain the impregnating capacity and leaching behaviours of heavy metals in the resulting sewage sludge char (SSC). Meanwhile, scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to detect the heavy metal phase in the SSC. The results showed that within 400-800°C and an impregnating concentration ≨0.5wt%, more than 90% of the externally impregnated Cu and Pb were remained in the SSC and immobilized. And higher temperatures helped produce non-hazardous SSC. In addition, SEM and XRD analyses revealed that externally impregnated heavy metals could be converted into stable forms and evenly distributed throughout the SSC. In the second step municipal solid waste incineration fly ash (FA) was kneaded into SS and subjected to carbonization; it has been proved that the heavy metals in FA can be well immobilized in the resulting char when FA: SS mass ratio is 1:5. Those results show that sewage sludge can be co-carbonized with wastes contaminated with heavy metals to achieve co-disposal. Copyright © 2016 Elsevier B.V. All rights reserved.

Preparation and characterization of activated carbon produced from pomegranate seeds by ZnCl 2 activation

Science.gov (United States)

Uçar, Suat; Erdem, Murat; Tay, Turgay; Karagöz, Selhan

2009-08-01

In this study, pomegranate seeds, a by-product of fruit juice industry, were used as precursor for the preparation of activated carbon by chemical activation with ZnCl 2. The influence of process variables such as the carbonization temperature and the impregnation ratio on textural and chemical-surface properties of the activated carbons was studied. When using the 2.0 impregnation ratio at the carbonization temperature of 600 °C, the specific surface area of the resultant carbon is as high as 978.8 m 2 g -1. The results showed that the surface area and total pore volume of the activated carbons at the lowest impregnation ratio and the carbonization temperature were achieved as high as 709.4 m 2 g -1 and 0.329 cm 3 g -1. The surface area was strongly influenced by the impregnation ratio of activation reagent and the subsequent carbonization temperature.

Study on adsorption characteristics and deterioration patterns of an impregnated active carbon under a simulated service condition of the filtering system at a nuclear power plant

International Nuclear Information System (INIS)

Kim, You Sun

1989-01-01

In order to study the relative adsorption pattern of organic iodides with an impregnated active carbon, organic iodides were reacted with TEDA(Triethylenediamine) in presence of methanol or hydrocarbons. The prepared salts or complexes were subjected to the radioisotope exchange reaction with CH 3 131 I, which could show the tendency of these compounds towards an isotopic exchange reaction. 1:1 organic salts were further prepared to confirm the adsorption pattern of an impregnated carbon (TEDA + KI system) under a dried air flow at 50 degree C. Impregnated active carbons such as KI 3 , TEDA + KI, and Dimethyl iodide of TEDA were subjected to the deterioration study under ASTM D 3803-86 conditions. A severe deterioration was observed in case of KI 3 , whereas it was relatively minor in cases of TEDA + KI and Dimethyl iodide of TEDA. The deteriorated samples were subjected to the study of radioactive methyl iodide penetration. Under the condition of ASTM D 3803-86 method A, the deteriorated sample could not show the penetration higher than that of the none deteriorated sample, but the penetration of the former sample was markedly increased as the methyl iodide's concentration was increased, which indicated a significant damage of the adsorption characteristics of the former. Three kinds of impregnated carbon such as TEDA + KI, Dimethyl iodide of TEDA, and monomethyl iodide of TEDA were prepared and their feasibilities of being applied for a ESF filter system were discussed comparing their physical and adsorption characteristics

Monoliths of activated carbon from coconut shell and impregnation with nickel and copper

International Nuclear Information System (INIS)

Giraldo, Liliana; Moreno, Juan

2008-01-01

A series of different monoliths of activated carbon were prepared from coconut shell By means of chemical activation with phosphoric acid at different concentrations Without using binders or plastics. The monolith that developed the biggest surface area was impregnated by humidic route with solutions of Ni and Cu at different molar relations. The structures were characterized by N2 adsorption at 77 K, and the morphology was explored by means of scanning electron microscopy. The carbonaceous materials obtained, Nickel-Copper-Monolith, were analyzed by Thermal Programmed Reduction (TPR). The experimental results indicated that the activation with the acid generated a micro porosity, with micropores volume between 0.40 and 0.81 cm 3 g-1 and surface areas between 703 and 1450 m 2 g-1, and a good mechanical properties. It shows that, both the copper and the nickel, are fixed to the monolith and TPR's results are interpreted when these molar relation are modified.

Activated carbon fibers and engineered forms from renewable resources

Science.gov (United States)

Baker, Frederick S

2013-02-19

A method of producing activated carbon fibers (ACFs) includes the steps of providing a natural carbonaceous precursor fiber material, blending the carbonaceous precursor material with a chemical activation agent to form chemical agent-impregnated precursor fibers, spinning the chemical agent-impregnated precursor material into fibers, and thermally treating the chemical agent-impregnated precursor fibers. The carbonaceous precursor material is both carbonized and activated to form ACFs in a single step. The method produces ACFs exclusive of a step to isolate an intermediate carbon fiber.

Factors affecting the retention of methyl iodide by iodide-impregnated carbon

International Nuclear Information System (INIS)

Hyder, M.L.; Malstrom, R.A.

1991-01-01

This paper comprises two sets of studies of methyl iodide retention by iodide-impregnated carbon. In the first of these, the retention of the methyl iodide on the carbon surface and its subsequent evolution were observed directly by a technique of combustion and phosphorescence. In the second, the methyl iodide retention in a standard test was compared with surface area measurements and the concentration of unreacted iodine. A correlation among these parameters was identified and characterized. Carbon quality was varied through the selection of used material with differing service histories. Air from the Savannah River Site reactor buildings is vented through carbon beds for control of radioiodine before release to the atmosphere. The carbon used is North American Carbon Co. type GX-176 coconut shell carbon impregnated with 1% triethylenedimaine (TEDA) and 2% potassium iodide by weight. Replacement intervals for the carbon have been as long as thirty months. Analysis of samples withdrawn at much shorter times has shown that the TEDA is lost after a few months, and the performance of the carbon for methyl iodide retention is dependent on the iodide impregnant. Efficient methyl iodide retention is not a requirement for carbon in this service; however, methyl iodide retention as measured by the ASTM Test D3803 (method B) has been found to correlate well with other desirable properties of the carbon such as radiation stability. The studies undertaken here were intended to shed light on the changes taking place in this carbon during long-term service and to provide a basis for simpler measurements of carbon quality

Extraction of organic materials from red water by metal-impregnated lignite activated carbon

Energy Technology Data Exchange (ETDEWEB)

Wei, Fangfang [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Zhang, Yihe, E-mail: zyh@cugb.edu.cn [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Lv, Fengzhu [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Ye, Zhengfang, E-mail: zhengfangye@163.com [Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences of the Ministry of Education, Peking University, Beijing 100871 (China)

2011-12-15

Highlights: Black-Right-Pointing-Pointer Metal-impregnated lignite activated carbon was investigated as adsorbent. Black-Right-Pointing-Pointer Adsorbent for the extraction of organic materials from 2,4,6-trinitrotoluene (TNT) red water. Black-Right-Pointing-Pointer Effects of different metals on the extraction were investigated and discussed. Black-Right-Pointing-Pointer Many loading factors of Cu{sup 2+} were found having great influences on the extraction. Black-Right-Pointing-Pointer Extraction performances and mechanism of TNT red water on Cu/LAC were investigated. - Abstract: Extraction of organic materials from 2,4,6-trinitrotoluene (TNT) red water by lignite activated carbon (LAC) impregnated with Cu{sup 2+}, Ba{sup 2+}, Sn{sup 2+}, Fe{sup 3+}, Ca{sup 2+} and Ag{sup +} was investigated. The affinity to organic materials in red water was found to follow the order: Cu/LAC > Sn/LAC > Ag/LAC > Ba/LAC > Fe/LAC > Ca/LAC, which was explained by the hard and soft acid base (HSAB) theory. Cu{sup 2+} showed the best performance and several parameters were further studied. X-ray photoelectron spectroscopy (XPS) verified effective loading of Cu{sup 2+} on the LAC surface. The water quality before and after treated by Cu/LAC was evaluated using high performance liquid chromatograph, Gas Chromatography/Mass Spectroscopy (GC/MS), UV-vis spectroscopy and other analyses. The extraction performances and mechanism of organic materials on Cu/LAC were investigated through static methods. The experimental results showed that Cu/LAC possessed stronger extraction ability for the sulfonated nitrotoluenes than the non-sulfonated nitrotoluenes, the kinetic data fitted the pseudo-second-order kinetic model well. In addition, the leaching out of Cu{sup 2+} from Cu/LAC was found much lower in the 100 times diluted red water (0.074%) than in the raw water (10.201%). Column adsorptions with more concentrated red water were also studied. Finally, Cu/LAC was observed to possess excellent

Preparation of iron oxide-impregnated spherical granular activated carbon-carbon composite and its photocatalytic removal of methylene blue in the presence of oxalic acid.

Science.gov (United States)

Kadirova, Zukhra C; Hojamberdiev, Mirabbos; Katsumata, Ken-Ichi; Isobe, Toshihiro; Matsushita, Nobuhiro; Nakajima, Akira; Sharipov, Khasan; Okada, Kiyoshi

2014-01-01

The spherical granular activated carbon-carbon composites (GAC-Fe) with different iron oxide contents (Fe mass% = 0.6-10) were prepared by a pore volume impregnation method. The X-ray diffraction (XRD), scanning electron microscopy (SEM), and N2-adsorption results confirm the presence of amorphous iron oxide, pyrolytic carbon, and graphitized globular carbon nanoparticles covered with amorphous carbon in the CAG-Fe. The rate of photodegradation of methylene blue (MB) in aqueous solution under UV light in the presence of oxalic acid correlates with porosity of the prepared materials. The total MB removal includes the combination of adsorption and photodegradation without the addition of H2O2. The results of total organic carbon (TOC) analysis reveal that the decolorization of MB in aqueous solution containing oxalic acid corresponds to the decomposition of organic compounds to CO2 and H2O.

Influence of aging on the retention of CH3131I by various empregnated activated carbons

International Nuclear Information System (INIS)

Deuber, H.

1986-08-01

Nuclear power plants are equipped with iodine filters containing impregnated activated carbons to keep the release of airborne radioiodine as low as reasonably achievable. Impregnated activated carbons are known to age, i.e. to deteriorate in performance with respect to the retention of radioiodine, particularly in iodine filters that are continuously operated (e.g. containment exhaust air filters of pressurized water reactors). The aging of carbons in iodine filters is essentially due to the adsorption of organic compounds (e.g. solvents) and of inorganic compounds (e.g. Osub(x), SO 2 , NOsub(x)). In the first case the effective surface of the carbon is lowered. In the second case reactions with carbon as well as with the impregnant can occur. In iodine filters various impregnated activated carbons are used differing e.g. in base material, grain size and impregnant. In recent years new impregnated activated carbons were developed. Therefore, investigations are performed to provide comparative data on the aging of a variety of commercial impregnated activated carbons from several countries under relevant conditions. The data relate to the retention of methyl iodide (CH 3 I-131). The investigations cover the aging of 15 different impregnated activated carbons in the containment exhaust air of a typical German pressurized water reactor over periods of up to 9 months

Performance of Conformable Phenolic Impregnated Carbon Ablator in Aerothermal Environments

Science.gov (United States)

Thornton, Jeremy; Fan, Wendy; Stackpoole, Mairead; Kao, David; Skokova, Kristina; Chavez-Garcia, Jose

2012-01-01

Conformable Phenolic Impregnated Carbon Ablator, a cousin of Phenolic Impregnated Carbon Ablator (PICA), was developed at NASA Ames Research Center as a lightweight thermal protection system under the Fundamental Aeronautics Program. PICA is made using a brittle carbon substrate, which has a very low strain to failure. Conformable PICA is made using a flexible carbon substrate, a felt in this case. The flexible felt significantly increases the strain to failure of the ablator. PICA is limited by its thermal mechanical properties. Future NASA missions will require heatshields that are more fracture resistant than PICA and, as a result, NASA Ames is working to improve PICA's performance by developing conformable PICA to meet these needs. Research efforts include tailoring the chemistry of conformable PICA with varying amounts of additives to enhance mechanical properties and testing them in aerothermal environments. This poster shows the performance of conformable PICA variants in arc jets tests. Some mechanical and thermal properties will also be presented.

Reactions of sulphur mustard on impregnated carbons.

Science.gov (United States)

Prasad, G K; Singh, Beer

2004-12-31

Activated carbon of surface area 1100 m2/gm is impregnated with 4% sodium hydroxide plus 3% Cr(VI) as CrO3 with and without 5% ethylene diamine (EDA), 4% magnesium nitrate and 5% ruthenium chloride by using their aqueous solutions. These carbons are characterized for surface area analysis by BET conventional method and exposed to the vapours of sulphur mustard (HD) at room temperature (30 degrees C). After 24 h, the reaction products are extracted in dichloromethane and analyzed using gas chromatography and mass spectrometry (GC-MS). Hemisulphur mustard, thiodiglycol, 1,4-oxathiane are observed to be the products of reaction between sulphur mustard and NaOH/CrO3/C system, whereas on NaOH/CrO3/EDA/C system HD reacted to give 1,4-thiazane. On Mg(NO3)2/C system it gave hemisulphur mustard and thiodiglycol. On RuCl3/C system it degraded to divinyl sulphone. Residual sulphur mustard is observed along with reaction products in all systems studied. Reaction mechanisms are also proposed for these interesting surface reactions. Above-mentioned carbons can be used in filtration systems for protection against hazardous gases such as sulphur mustard.

Reactions of sulphur mustard on impregnated carbons

International Nuclear Information System (INIS)

Prasad, G.K.; Singh, Beer

2004-01-01

Activated carbon of surface area 1100 m 2 /gm is impregnated with 4% sodium hydroxide plus 3% Cr(Vi) as CrO 3 with and without 5% ethylene diamine (EDA), 4% magnesium nitrate and 5% ruthenium chloride by using their aqueous solutions. These carbons are characterized for surface area analysis by BET conventional method and exposed to the vapours of sulphur mustard (HD) at room temperature (30 deg. C). After 24 h, the reaction products are extracted in dichloromethane and analyzed using gas chromatography and mass spectrometry (GC-MS). Hemisulphur mustard, thiodiglycol, 1,4-oxathiane are observed to be the products of reaction between sulphur mustard and NaOH/CrO 3 /C system, whereas on NaOH/CrO 3 /EDA/C system HD reacted to give 1,4-thiazane. On Mg(NO 3 ) 2 /C system it gave hemisulphur mustard and thiodiglycol. On RuCl 3 /C system it degraded to divinyl sulphone. Residual sulphur mustard is observed along with reaction products in all systems studied. Reaction mechanisms are also proposed for these interesting surface reactions. Above-mentioned carbons can be used in filtration systems for protection against hazardous gases such as sulphur mustard

Surfactant-impregnated activated carbon for enhanced adsorptive removal of Ce(IV) radionuclides from aqueous solutions

International Nuclear Information System (INIS)

Mahmoud, Mamdoh R.; Sharaf El-deen, Gehan E.; Soliman, Mohamed A.

2014-01-01

Highlights: • Activated carbon (AC) was impregnated in this work with CTAB and NaLS surfactants. • The materials were evaluated as a sorbent for adsorption of Ce(IV) radionuclides. • Adsorption capacity of AC–NaLS for Ce(IV) is two-times the capacity of AC. • The kinetic and equilibrium data are fitted to pseudo-second-order and D–R models. • The results suggest the applicability of surface modified AC for waste treatment. - Abstract: The surfactants cetyltrimethylammonium bromide (CTAB) and sodium lauryl sulfate (NaLS) were utilized for modifying the activated carbon’s surface. The materials were characterized using BET–N 2 , scanning electron microscope, and Fourier transform infrared (FT-IR) spectroscopy. Adsorption of Ce(IV) radionuclides from aqueous solutions by activated carbon (AC) and surfactant-impregnated AC was studied. The obtained data showed that adsorption of Ce(IV) is strongly dependent on the solution pH and AC–NaLS exhibits the widest pH-range of maximum removal. The experimental adsorption capacity of AC–NaLS (0.069 mmol/g) for Ce(IV) is found to be nearly twice greater than that of AC (0.036 mmol/g). The adsorption kinetics of Ce(IV) onto AC and AC–NaLS were analyzed by linear and non-linear fittings to the pseudo-first-order, pseudo-second-order and Elovich kinetic models. Of these models, the pseudo-second-order is the best kinetic expression for describing the experimental data. The diffusion studies indicated that adsorption of Ce(IV) radionuclides on AC and AC–NaLS is controlled by film diffusion. Linear and non-linear fittings of the adsorption equilibrium data for Ce(IV) onto AC and AC–NaLS revealed that the Dubinin–Radushkevich (D–R) isotherm model fits the experimental data better than Freundlich and Langmuir models. The values of adsorption free energy, E, calculated from both linear and non-linear methods suggested that Ce(IV) radionuclides are physically adsorbed onto AC and AC–NaLS

Silica-coated multi-walled carbon nanotubes impregnated with polyethyleneimine for carbon dioxide capture under the flue gas condition

Energy Technology Data Exchange (ETDEWEB)

Lee, Min-Sang; Park, Soo-Jin, E-mail: sjpark@inha.ac.kr

2015-03-15

In this study, silica-coated multi-walled carbon nanotubes impregnated with polyethyleneimine (PEI) were prepared via a two-step process: (i) hydrolysis of tetraethylorthosilicate onto multi-walled carbon nanotubes, and (ii) impregnation of PEI. The adsorption properties of CO{sub 2} were investigated using CO{sub 2} adsorption–desorption isotherms at 298 K and thermogravimetric analysis under the flue gas condition (15% CO{sub 2}/85% N{sub 2}). The results obtained in this study indicate that CO{sub 2} adsorption increases after impregnation of PEI. The increase in CO{sub 2} capture was attributed to the affinity between CO{sub 2} and the amine groups. CO{sub 2} adsorption–desorption experiments, which were repeated five times, also showed that the prepared adsorbents have excellent regeneration properties. - Graphical abstract: Fabrication and CO{sub 2} adsorption process of the S-MWCNTs impregnated with PEI. - Highlights: • Silica coated-MWCNT impregnated with PEI was synthesized. • Amine groups of PEI gave CO{sub 2} affinity sites on MWCNT surfaces. • The S-MWCNT/PEI(50) exhibited the highest CO{sub 2} adsorption capacity.

Effect of impregnation protocol in the metallic sites of Pt–Ag/activated carbon catalysts for water denitration

Energy Technology Data Exchange (ETDEWEB)

Aristizábal, A. [Departament d’Enginyeria Química, Universitat Rovira i Virgili, Campus Sescelades, Av. Països Catalans 26, 43007 Tarragona (Spain); Contreras, S., E-mail: sandra.contreras@urv.cat [Departament d’Enginyeria Química, Universitat Rovira i Virgili, Campus Sescelades, Av. Països Catalans 26, 43007 Tarragona (Spain); Divins, N.J.; Llorca, J. [Institut de Tècniques Energètiques i Centre de Recerca en Nanoenginyeria, Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain); Medina, F. [Departament d’Enginyeria Química, Universitat Rovira i Virgili, Campus Sescelades, Av. Països Catalans 26, 43007 Tarragona (Spain)

2014-04-01

Highlights: • Mean particle size is tuned by the Pt precursor. H{sub 2}PtCl{sub 6} leads to smaller size. • H{sub 2}PtCl{sub 6} leads to higher extent of Pt–Ag particles with a composition richer in silver. • Pt(NH{sub 3}){sub 4}(NO{sub 3}){sub 2} leads to Ag{sup 0} particles and some Pt–Ag ensembles in less extent. • Nitrate and nitrite rates are linearly related to mean metal particle size. • Physical mixture of catalysts enhances N{sub 2} selectivities. - Abstract: The influence of the Pt precursor and the impregnation protocol in the catalytic behavior of 3%Pt–1.5%Ag supported on activated carbon for water denitration in a continuous reactor was studied. Pt(NH{sub 3}){sub 4}(NO{sub 3}){sub 2} and H{sub 2}PtCl{sub 6} were selected as Pt precursors. Five protocols were investigated: sequential impregnations (both sequences), co-impregnation, physical mixture of monometallic catalysts, and physical mixture of a bimetallic catalyst with a Pt monometallic catalyst. The samples were characterized by XRD, XPS, TPR, HRTEM and physisorption. It was found that the catalytic activity strongly depends on the synthesis protocol and the Pt precursor, which modify the particle size. Higher nitrate rates are achieved using H{sub 2}PtCl{sub 6} than Pt(NH{sub 3}){sub 4}(NO{sub 3}){sub 2}; this is mainly related to the smaller metal particle size of the former, evidenced by HRTEM. Nitrate consumption rate is directly related with the mean particle size. The physical mixture of monometallic catalysts resulted in the highest nitrogen rate.

CO{sub 2} capture using fly ash-derived activated carbons impregnated with low molecular mass amines

Energy Technology Data Exchange (ETDEWEB)

Smith, K.M.; Arenillas, A.; Drage, T.C.; Snape, C.E. [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre

2005-07-01

Two different approaches to develop high capacity CO{sub 2} sorbents are presented. Firstly, the modification of the surface chemistry of low cost carbons by impregnation with a basic nitrogen-containing polymer (i.e.polyethylenimine) is described. Relatively low molecular mass (MM) amines, namely diethanolamine (DEA, MM 105) and tetraethylenepentaamineacrylonitrile (TEPAN, MM 311) are used to produce high capacity CO{sub 2} sorbents from activated carbons derived from unburned carbon in fly ash, which have low mesoporosities. The CO{sub 2} adsorption capacity and thermal stability of the prepared sorbents was measured as a function of temperature in a thermogravimetric analyser. The results indicate that TEPAN is more effective than DEA; at a temperature of 75{sup o}C, fly ash-derived activated carbons loaded with TEPAN achieved CO{sub 2} adsorption capacities in excess of 5 wt%, which compares fabvourably with the CO{sub 2} absorption capacity of 6.5 wt% achieved with a mesoporous silica loaded with TEPAN, and outperforms fly ash-derived activated carbons loaded with PEI. TEPAN has also been shown to have a higher thermal stability than DEA. The second approach involves the development of high nitrogen content carbon matrix adsorbents by carbonisation and subsequent thermal or chemical activation of a range of materials (polyacrylonitrile, glucose-amine mixtures, melamine and urea/melamine-formaldehyde resins). The results show that although the amount of nitrogen incorporated to the final adsorbent is important, the N-functionality seems to be more relevant for increasing CO{sub 2} uptake. However, the adsorbent obtained from carbazole-sugar co-pyrolysis, despite the lower amount of N incorporated, shows high CO{sub 2} uptake, up to 9 wt%, probably because the presence of more basic functionalities as determined by XPS analysis. 9 refs., 2 figs.

Activated carbon material

International Nuclear Information System (INIS)

Evans, A.G.

1978-01-01

Activated carbon particles for use as iodine trapping material are impregnated with a mixture of selected iodine and potassium compounds to improve the iodine retention properties of the carbon. The I/K ratio is maintained at less than about 1 and the pH is maintained at above about 8.0. The iodine retention of activated carbon previously treated with or coimpregnated with triethylenediamine can also be improved by this technique. Suitable flame retardants can be added to raise the ignition temperature of the carbon to acceptable standards

High activity PtRu/C catalysts synthesized by a modified impregnation method for methanol electro-oxidation

International Nuclear Information System (INIS)

Ma Liang; Liu Changpeng; Liao Jianhui; Lu Tianhong; Xing Wei; Zhang Jiujun

2009-01-01

A modified impregnation method was used to prepare highly dispersive carbon-supported PtRu catalyst (PtRu/C). Two modifications to the conventional impregnation method were performed: one was to precipitate the precursors ((NH 4 ) 2 PtCl 6 and Ru(OH) 3 ) on the carbon support before metal reduction; the other was to add a buffer into the synthetic solution to stabilize the pH. The prepared catalyst showed a much higher activity for methanol electro-oxidation than a catalyst prepared by the conventional impregnation method, even higher than that of current commercially available, state-of-the-art catalysts. The morphology of the prepared catalyst was characterized using TEM and XRD measurements to determine particle sizes, alloying degree, and lattice parameters. Electrochemical methods were also used to ascertain the electrochemical active surface area and the specific activity of the catalyst. Based on XPS measurements, the high activity of this catalyst was found to originate from both metallic Ru (Ru 0 ) and hydrous ruthenium oxides (RuO x H y ) species on the catalyst surface. However, RuO x H y was found to be more active than metallic Ru. In addition, the anhydrous ruthenium oxide (RuO 2 ) species on the catalyst surface was found to be less active.

Optimization of process condition for the preparation of amine-impregnated activated carbon developed for CO2 capture and applied to methylene blue adsorption by response surface methodology.

Science.gov (United States)

Das, Dipa; Meikap, Bhim C

2017-10-15

The present research describes the optimal adsorption condition for methylene blue (MB). The adsorbent used here was monoethanol amine-impregnated activated carbon (MEA-AC) prepared from green coconut shell. Response surface methodology (RSM) is the multivariate statistical technique used for the optimization of the process variables. The central composite design is used to determine the effect of activation temperature, activation time and impregnation ratio on the MB removal. The percentage (%) MB adsorption by MEA-AC is evaluated as a response of the system. A quadratic model was developed for response. From the analysis of variance, the factor which was the most influential on the experimental design response has been identified. The optimum condition for the preparation of MEA-AC from green coconut shells is the temperature of activation 545.6°C, activation time of 41.64 min and impregnation ratio of 0.33 to achieve the maximum removal efficiency of 98.21%. At the same optimum parameter, the % MB removal from the textile-effluent industry was examined and found to be 96.44%.

Fracture in Phenolic Impregnated Carbon Ablator

Science.gov (United States)

Agrawal, Parul; Chavez-Garcia, Jose; Pham, John

2013-01-01

This paper describes the development of a novel technique to understand the failure mechanisms inside thermal protection materials. The focus of this research is on the class of materials known as phenolic impregnated carbon ablators. It has successfully flown on the Stardust spacecraft and is the thermal protection system material chosen for the Mars Science Laboratory and SpaceX Dragon spacecraft. Although it has good thermal properties, structurally, it is a weak material. To understand failure mechanisms in carbon ablators, fracture tests were performed on FiberForm(Registered TradeMark) (precursor), virgin, and charred ablator materials. Several samples of these materials were tested to investigate failure mechanisms at a microstructural scale. Stress-strain data were obtained simultaneously to estimate the tensile strength and toughness. It was observed that cracks initiated and grew in the FiberForm when a critical stress limit was reached such that the carbon fibers separated from the binder. However, both for virgin and charred carbon ablators, crack initiation and growth occurred in the matrix (phenolic) phase. Both virgin and charred carbon ablators showed greater strength values compared with FiberForm samples, confirming that the presence of the porous matrix helps in absorbing the fracture energy.

Impregnation of Ibuprofen into Polycaprolactone using supercritical carbon dioxide

International Nuclear Information System (INIS)

Yoganathan, Roshan; Mammucari, Raffaella; Foster, Neil R

2010-01-01

Polycaprolactone (PCL) is a Food and Drug Administration (FDA) approved biodegradable polyester used in tissue engineering applications. Ibuprofen is an anti-inflammatory drug which has good solubility in supercritical CO 2 (SCCO 2 ). The solubility of CO 2 in PCL allows for the impregnation of CO 2 -soluble therapeutic agents into the polymer via a supercritical fluid (SCF) process. Polymers impregnated with bio-active compounds are highly desired for medical implants and controlled drug delivery. In this study, the use of CO 2 to impregnate PCL with ibuprofen was investigated. The effect of operating conditions on the impregnation of ibuprofen into PCL was investigated over two pressure and two temperature levels, 150bar and 200bar, 35 0 C and 40 0 C, respectively. Polycaprolactone with drug-loadings as high as 27% w/w were obtained. Impregnated samples exhibited controlled drug release profiles over several days.

Effect of impregnation pressure and time on the porosity, structure and properties of polyacrylonitrile-fiber based carbon composites

Energy Technology Data Exchange (ETDEWEB)

Venugopalan, Ramani, E-mail: rvg@barc.gov.in [Powder Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Roy, Mainak, E-mail: mainak73@barc.gov.in [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Thomas, Susy [High Pressure Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Patra, A.K. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sathiyamoorthy, D. [Powder Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Tyagi, A.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2013-02-15

Carbon–carbon composites may find applications in critical parts of advanced nuclear reactors. A series of carbon–carbon composites were prepared using polyacrylonitrile (PAN) based carbon fibers. The materials were densified by impregnating two-dimensional (2D) preforms with liquid phenol formaldehyde resin at different pressures and for different periods of time and then carbonizing those by slowly heating at 1000 °C. Effects of the processing parameters on the structure of the composites were extensively studied. The study showed conclusively that open porosity decreased with increasing impregnation pressure, whereas impregnation time had lesser effect. Matrix–resin bonding also improved at higher pressure. d{sub 002} spacing decreased and ordering along c-axis increased with concomitant increase in sp{sup 2}-carbon fraction at higher impregnation pressures. The fiber reinforced composites exhibited short range ordering of carbon atoms and satisfied structural conditions (d{sub 002} values) of amorphous carbon according to the turbostratic model for non-graphitic carbon materials. The composites had pellet-density of ∼85% of the theoretical value, low thermal expansion and negligible neutron-poisoning. They maintained structural integrity and retained disordered nature even on heat-treatment at ca. 1800 °C.

Effect of pore structure on the activated carbon's capability to sorb airborne methylradioiodine

International Nuclear Information System (INIS)

Juhola, A.J.; Friel, J.V.

1979-01-01

A study was conducted to determine the effect pore structure of activated carbons has on their capabiity to sorp airborne methylradioiodine. Six de-ashed carbons of very diverse pore structure were selected for study. Batches of each were impregnated with (1) 4.3% I 2 , (2) 5.6% KI, (3) 2% KI, (4) 3% KI to 2% I 2 , (5) 2% I 2 , and (6) 3.4% KIO 3 . Some carbon was reserved for testing without impregnant. Standard procedures at ambient temperature and pressure were followed in the methyliodide testing, with some changes only made to meet the requirements of the specialized study. The surface area of the open-pore volume, for KI impregnated carbons, determined the sorptive efficiency. This relationship is expressed by the equation ln p = ln a - ks, where p is the fraction of methyliodide penetrating the bed and s the surface area. The quantity (a) is associated with the macropore properties, and deterines the capability of the carbon to sorb at very high humidites (> 95% RH). Constant k is to a large degree dependent on the mean diameter of the micropores. Elemental iodine impregnated carbons were considerably less effective than those impregnated with KI, and their sorptive of methyliodide did not follow the above equation. Their activity could be increased by a second impregnation with KOH. KI impregnated carbons lost their activity when treated with HCl on converting the Ki to I 2 . The conversion of KI to I 2 by acid gases in nuclear power plants offers an explanation for the cause of carbon aging

Impregnation of Ibuprofen into Polycaprolactone using supercritical carbon dioxide

Energy Technology Data Exchange (ETDEWEB)

Yoganathan, Roshan; Mammucari, Raffaella; Foster, Neil R, E-mail: n.foster@unsw.edu.a [Supercritical Fluids Research Group, School of Chemical Sciences and Engineering, University of New South Wales, NSW 2052 (Australia)

2010-03-01

Polycaprolactone (PCL) is a Food and Drug Administration (FDA) approved biodegradable polyester used in tissue engineering applications. Ibuprofen is an anti-inflammatory drug which has good solubility in supercritical CO{sub 2} (SCCO{sub 2}). The solubility of CO{sub 2} in PCL allows for the impregnation of CO{sub 2}-soluble therapeutic agents into the polymer via a supercritical fluid (SCF) process. Polymers impregnated with bio-active compounds are highly desired for medical implants and controlled drug delivery. In this study, the use of CO{sub 2} to impregnate PCL with ibuprofen was investigated. The effect of operating conditions on the impregnation of ibuprofen into PCL was investigated over two pressure and two temperature levels, 150bar and 200bar, 35{sup 0}C and 40 {sup 0}C, respectively. Polycaprolactone with drug-loadings as high as 27% w/w were obtained. Impregnated samples exhibited controlled drug release profiles over several days.

Preparation of Activated Carbon from Maize Stems by Sulfuric Acids Activation and Their Application in Copper (II Ion Sorption

Directory of Open Access Journals (Sweden)

Erin Ryantin Gunawan

2010-04-01

Full Text Available Activated carbons were prepared from maize (Zea mays L. stems by sulfuric acids activation or chemical methods. The dry maize stems are usually used as low-value energy resources in many countries, burned in the field, or discarded, which are unfavorable to environment. This motivates the investigation of producing value-added products from the dry maize stems, such as activated carbons, as well as solving some environmental problems. The preparation process consisted of sulfuric acid impregnation at different impregnation ratio followed by carbonization at 250-400 oC for 1-4 h. The results show that the impregnation ratio was 1.25, the optimum activation temperature was 300 oC and the activation time was 1 h. The sorption capacity of the activated carbon was 25.1 mg/g.

Retention of gaseous fission products by pure and modified activated carbon

International Nuclear Information System (INIS)

Wilhelmova, L.; Cejnar, F.

1975-01-01

The results are reported of research into Czechoslovak-made activated carbon Desorex DB-2 and Supersorbon HS-1 and their retention properties. Krypton, xenon and helium of spectral purity were used in the investigation. The effect of surface impregnation was also studied on the retention efficiency of the activated carbon. It was found that the impregnation with alkali metal fluorides, such as RbF and CsF favourably affected the retention properties of the activated carbon as concerns gaseous fission products. (L.O.)

Catalytic fast pyrolysis of biomass impregnated with potassium phosphate in a hydrogen atmosphere for the production of phenol and activated carbon

Science.gov (United States)

Lu, Qiang; Zhang, Zhen-xi; Wang, Xin; Guo, Hao-qiang; Cui, Min-shu; Yang, Yong-ping

2018-02-01

A new technique was proposed to co-produce phenol and activated carbon (AC) from catalytic fast pyrolysis of biomass impregnated with K3PO4 in a hydrogen atmosphere, followed by activation of the pyrolytic solid residues. Lab-scale catalytic fast pyrolysis experiments were performed to quantitatively determine the pyrolytic product distribution, as well as to investigate the effects of several factors on the phenol production, including pyrolysis atmosphere, catalyst type, biomass type, catalytic pyrolysis temperature, and catalyst impregnation content. In addition, the pyrolytic solid residues were activated to prepare ACs with high specific surface areas. The results indicated that phenol could be obtained due to the synergistic effects of K3PO4 and hydrogen atmosphere, with the yield and selectivity reaching 5.3 wt% and 17.8% from catalytic fast pyrolysis of poplar wood with 8 wt% K3PO4 at 550 oC in a hydrogen atmosphere. This technique was adaptable to different woody materials for phenol production. Moreover, gas product generated from the pyrolysis process was feasible to be recycled to provide the hydrogen atmosphere, instead of extra hydrogen supply. In addition, the pyrolytic solid residue was suitable for AC preparation, using CO2 activation method, the specific surface area was as high as 1605 m2/g.

Production and characterization of activated carbon from a ...

African Journals Online (AJOL)

In this study, the use of a bituminous coal for the production of activated carbons with chemical activation was investigated. The effects of process variables such as chemical reagents, activation temperature, impregnation ratio and carbonization temperature were investigated to optimize these parameters. The resultant ...

Impregnation of cinnamaldehyde into cassava starch biocomposite films using supercritical fluid technology for the development of food active packaging.

Science.gov (United States)

de Souza, Ana Cristina; Dias, Ana M A; Sousa, Hermínio C; Tadini, Carmen C

2014-02-15

In this work, supercritical solvent impregnation (SSI) has been tested for the incorporation of natural compounds into biocomposite materials for food packaging. Cinnamaldehyde, with proved antimicrobial activity against fungi commonly found in bread products, was successfully impregnated on biocomposite cassava starch based materials using supercritical carbon dioxide as solvent. Different process experimental conditions were tested (pressure, impregnation time and depressurization rate) at a fixed temperature (35 °C) in order to study their influence on the amount of impregnated cinnamaldehyde as well as on the morphology of the films. Results showed that all conditions permitted to impregnate antimicrobial active amounts superior to those previously obtained using conventional incorporation methods. Moreover, a significant decrease of the equilibrium water vapor sorption capacity and water vapor permeability of the films was observed after SSI processing which is a clear advantage of the process, considering the envisaged applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

O2 electrocatalysis in acid media on iron naphthalocyanine impregnations. Effect of nitric acid treatment on different carbon black supports

NARCIS (Netherlands)

Coowar, F.; Contamin, O.; Savy, M.; Scarbeck, G.; van den Ham, D.; Riga, J.; Verbist, J.J.

1991-01-01

O2 electrocatalysis on (2,3)FeNPc impregnations on different carbon blacks was investigated in H2SO4 medium. The effect of nitric acid treatment on the carbon black support is to enhance both the activity and stability of the catalyst. Moreover, as seen by XPS, the dissolution of iron is impeded by

Modifying an Active Compound’s Release Kinetic Using a Supercritical Impregnation Process to Incorporate an Active Agent into PLA Electrospun Mats

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Carol López de Dicastillo

2018-04-01

Full Text Available The main objective of this work was to study the release of cinnamaldehyde (CIN from electrospun poly lactic acid (e-PLA mats obtained through two techniques: (i direct incorporation of active compound during the electrospinning process (e-PLA-CIN; and (ii supercritical carbon dioxide (scCO2 impregnation of CIN within electrospun PLA mats (e-PLA/CINimp. The development and characterization of both of these active electrospun mats were investigated with the main purpose of modifying the release kinetic of this active compound. Morphological, structural, and thermal properties of these materials were also studied, and control mats e-PLA and e- PLA CO 2 were developed in order to understand the effect of electrospinning and scCO2 impregnation, respectively, on PLA properties. Both strategies of incorporation of this active compound into PLA matrix resulted in different morphologies that influenced chemical and physical properties of these composites and in different release kinetics of CIN. The electrospinning and scCO2 impregnation processes and the presence of CIN altered PLA thermal and structural properties when compared to an extruded PLA material. The incorporation of CIN through scCO2 impregnation resulted in higher release rate and lower diffusion coefficients when compared to active electrospun mats with CIN incorporated during the electrospinning process.

Effect of Na+ impregnated activated carbon on the adsorption of NH4(+)-N from aqueous solution.

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Shi, Mo; Wang, Zhengfang; Zheng, Zheng

2013-08-01

Two kinds of activated carbons modified by Na+ impregnation after pre-treatments involving oxidation by nitric acid or acidification by hydrochloric acid (denoted as AC/N-Na and AC/HCl-Na, respectively), were used as adsorbents to remove NH4(+)-N. The surface features of samples were investigated by BET, SEM, XRD and FT-IR. The adsorption experiments were conducted in equilibrium and kinetic conditions. Influencing factors such as initial solution pH and initial concentration were investigated. A possible mechanism was proposed. Results showed that optimal NH4(+)-N removal efficiency was achieved at a neutral pH condition for the modified ACs. The Langmuir isotherm adsorption equation provided a better fit than other models for the equilibrium study. The adsorption kinetics followed both the pseudo second-order kinetics model and intra-particle kinetic model. Chemical surface analysis indicated that Na+ ions form ionic bonds with available surface functional groups created by pre-treatment, especially oxidation by nitric acid, thus increasing the removal efficiency of the modified ACs for NH4(+)-N. Na(+)-impregnated ACs had a higher removal capability in removing NH4(+)-N than unmodified AC, possibly resulting from higher numbers of surface functional groups and better intra-particle diffusion. The good fit of Langmuir isotherm adsorption to the data indicated the presence of monolayer NH4(+)-N adsorption on the active homogenous sites within the adsorbents. The applicability of pseudo second-order and intra-particle kinetic models revealed the complex nature of the adsorption mechanism. The intra-particle diffusion model revealed that the adsorption process consisted not only of surface adsorption but also intra-particle diffusion.

Dielectric microwave absorbing material processed by impregnation of carbon fiber fabric with polyaniline

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Luiza de Castro Folgueras

2007-03-01

Full Text Available It is a known fact that the adequate combination of components and experimental conditions may produce materials with specific requirements. This study presents the effect of carbon fiber fabric impregnation with polyaniline conducting polymer aiming at the radar absorbing material processing. The experiments consider the sample preparation with one and two impregnations. The prepared samples were evaluated by reflectivity measurements, in the frequency range of 8-12 GHz and scanning electron microscopy analyses. The correlation of the results shows that the quantity of impregnated material influences the performance of the processed microwave absorber. This study shows that the proposed experimental route provides flexible absorbers with absorption values of the incident radiation close to 87%.

Adsorption of low concentration ceftazidime from aqueous solutions using impregnated activated carbon promoted by Iron, Copper and Aluminum

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Hu, Xiang; Zhang, Hua; Sun, Zhirong

2017-01-01

In this paper, three impregnated activated carbon IAC (AC-Cu, AC-Fe, and AC-Al) promoted by Iron, Copper and Aluminum were used for adsorption of ceftazidime. Iron(III), Copper(II) and Aluminum(III) nitrate were used as an impregnant. The IACs were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS).The influence of factors, such as ion strength, pH, temperature, initial concentration, and concentration of natural organic matter organic matter on the adsorption process were studied. The adsorption kinetics and isotherms of ceftazidime were studied for the three IACs. The results showed that the adsorption was accurately represented by pseudo-second order model. Under different temperature, the maximum adsorption quantity of ceftazidime on AC-Cu calculated by pseudo-second order kinetic model were 200.0 mg g-1 (298 K), 196.1 mg g-1 (303 K) and 185.2 mg g-1 (308 K). It was much higher than that of AC-Fe and AC-Al. And the process was controlled by both film diffusion and intra particle mass transport. The results also showed that, the Freundlich and Temkin isotherm fit the adsorption well.

Characteristics of activated carbon resulted from pyrolysis of the oil palm fronds powder

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Maulina, S.; Iriansyah, M.

2018-02-01

Activated carbon is the product of a charcoal impregnation process that has a higher absorption capacity and has more benefits than regular char. Therefore, this study aims to cultivate the powder of oil palm fronds into activated carbon that meets the requirements of Standard National Indonesia 06-3730-1995. To do so, the carbonization process of the powder of oil palm fronds was carried out using a pyrolysis reactor for 30 minutes at a temperature of 150 °C, 200 °C, and 250 °C in order to produce activated char. Then, the char was impregnated using Phosphoric Acid activator (H3PO4) for 24 hours. Characteristics of activated carbon indicate that the treatment of char by chemical activation of oil palm fronds powder has an effect on the properties of activated carbon. The activated carbons that has the highest absorption properties to Iodine (822.91 mg/g) were obtained from the impregnation process with 15% concentration of Phosphoric Acid (H3PO4) at pyrolysis temperature of 200 °C. Furthermore, the activation process resulted in activated carbon with water content of 8%, ash content of 4%, volatile matter 39%, and fixed carbon 75%, Iodine number 822.91 mg/g.

Catalytic Fast Pyrolysis of Biomass Impregnated with Potassium Phosphate in a Hydrogen Atmosphere for the Production of Phenol and Activated Carbon

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Lu, Qiang; Zhang, Zhen-xi; Wang, Xin; Guo, Hao-qiang; Cui, Min-shu; Yang, Yong-ping

2018-01-01

A new technique was proposed to co-produce phenol and activated carbon (AC) from catalytic fast pyrolysis of biomass impregnated with K3PO4 in a hydrogen atmosphere, followed by activation of the pyrolytic solid residues. Lab-scale catalytic fast pyrolysis experiments were performed to quantitatively determine the pyrolytic product distribution, as well as to investigate the effects of several factors on the phenol production, including pyrolysis atmosphere, catalyst type, biomass type, catalytic pyrolysis temperature, and catalyst impregnation content. In addition, the pyrolytic solid residues were activated to prepare ACs with high specific surface areas. The results indicated that phenol could be obtained due to the synergistic effects of K3PO4 and hydrogen atmosphere, with the yield and selectivity reaching 5.3 wt% and 17.8% from catalytic fast pyrolysis of poplar wood with 8 wt% K3PO4 at 550°C in a hydrogen atmosphere. This technique was adaptable to different woody materials for phenol production. Moreover, gas product generated from the pyrolysis process was feasible to be recycled to provide the hydrogen atmosphere, instead of extra hydrogen supply. In addition, the pyrolytic solid residue was suitable for AC preparation, using CO2 activation method, the specific surface area was as high as 1,605 m2/g. PMID:29515994

Control of Effluent Gases from Solid Waste Processing using Impregnated Carbon Nanotubes

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Li, Jing; Fisher, John; Wignarajah, Kanapathipillai

2005-01-01

One of the major problems associated with solid waste processing technologies is effluent contaminants that are released in gaseous forms from the processes. This is a concern in both biological as well as physicochemical solid waste processing. Carbon dioxide (CO2), the major gas released, does not present a serious problem and there are currently in place a number of flight-qualified technologies for CO2 removal. However, a number of other gases, in particular NOx, SO2, NH3, and various hydrocarbons (e.g. CH4) do present health hazards to the crew members in space habitats. In the present configuration of solid waste processing in the International Space Station (ISS), some of these gases are removed by the Trace Contaminant Control System (TCCS), demands a major resupply. Reduction of the resupply can be effective by using catalyst impregnated carbon nanotubes. For example, NO decomposition to N2 and O2 is thermodynamically favored. Data showing decomposition of NO on metal impregnated carbon nanotubes is presented. Comparisons are made of the existing TCCS systems with the carbon nanotube based technology for removing NOx based on mass/energy penalties.

Effect of combined activation on the preparation of high porous active carbons from granulated post-consumer polyethyleneterephthalate

International Nuclear Information System (INIS)

Sych, N.V.; Kartel, N.T.; Tsyba, N.N.; Strelko, V.V.

2006-01-01

Activated carbons were prepared from granulated post-consumer PET by combined activation including heat treatment with sulphuric acid (chemical activation) followed by steam activation. The effect of activation time, temperature, impregnation coefficient in the activation process was studied in order to optimize those reception parameters. One of the most important parameter in combined activation of crushed PET was found to be impregnation coefficient. It was defined that the optimal impregnation coefficient is equal 28%. Activation temperature is another variability which has a significant effect on the pore volume evolution. The increasing of activation temperature enhances the surface area and pore volumes of active carbons. The yield of final product which composes of nearly 15% is the factor limited the activation temperature above 800 deg. C. Textural characteristics of the samples were carried out by performing N 2 adsorption isotherm at -196 deg. C. The obtained active carbons were mainly micro- and mesoporous and with BET apparent surface areas of up to 1030 m 2 /g. The adsorption capacity on methylene blue reaches 1.0 mmol/g, the sorption activity on iodine comes to 77%

Preparation and surface characterization of activated carbons from Euphorbia rigida by chemical activation with ZnCl2, K2CO3, NaOH and H3PO4

International Nuclear Information System (INIS)

Kılıç, Murat; Apaydın-Varol, Esin; Pütün, Ayşe Eren

2012-01-01

Highlights: ► An arid land plant evaluated as low cost activated carbon precursor. ► Four types of different chemical activation agents are used. ► Higher surface area (2600 m 2 /g) obtained by chemical activation. ► Obtained activated carbon can be effectively used as an adsorbent for the removal of toxic pollutants from aqueous solutions. - Abstract: Preparation of activated carbons from Euphorbia rigida by chemical activation with different impregnation agents and ratios was studied. ZnCl 2 , K 2 CO 3 , NaOH and H 3 PO 4 were used as chemical activation agents and four impregnation ratios (25–50–75–100%) by mass were applied on biomass. Activation is applied to impregnated biomass samples at 700 °C under sweeping gas in a fixed bed reactor. For determination of chemical and physical properties of the obtained activated carbons; elemental analysis was applied to determine the elemental composition (C, H, N, O) and FT-IR spectra was used to analyze the functional groups. BET equation was used to calculate the surface areas of activated carbons. For understanding the changes in the surface structure, activated carbons were conducted to Scanning Electron Microscopy (SEM). Maximum BET surface area (2613 m 2 /g) was reached with 75% K 2 CO 3 impregnated biomass sample. Experimental results showed that impregnation types and ratios have a significant effect on the pore structure of activated carbon and E. rigida seems to be an alternative precursor for commercial activated carbon production.

Removal of odor originating from kitchen wastewater treatment facilities by activated carbon impregnated iodic acid; Chubo haisui shori shisetsu kara hasseisuru akushu no yososan tenchaku kasseitan ni yoru jokyo

Energy Technology Data Exchange (ETDEWEB)

Yano, H.; Hashimoto, S.; Yonemura, S. [Shimizu Corp., Tokyo (Japan); Shoda, M. [Research Laboratory of Resources Utilization, Yokohama (Japan)

1997-07-10

Activated carbon impregnated iodic acid (deodorant D) was developed as a new deodorant. Deodorization performance of deodorant D as well as three kinds of commercial activated carbons (deodorant A, B and C) was tested for odors originating from the kitchen wastewater treatment facilities of one commercial building. The odor exhausted from this facility was medium concentration between 422 and 31,620. The main odorous compounds were hydrogen sulfide (0.076 to 15.7 ppm) and methyl mercaptan (not detected to 0.081 ppm). The hydrogen sulfide contribution to the odor concentration was about 90%. The main apparatuses from which the odors were originating were the raw water tank and the pressurized flotation tank. The total odor emission rate was between 10{sup 4.9} and 10{sup 5.7} Nm{sup 3}/min. For the performance test for deodorants, fixed bed adsorption experimental equipment was used, and the breakthrough time of odor concentration and hydrogen sulfide were used as indexes. Correlation between the contact time and the breakthrough time was observed for all of the deodorants. For a contact time of 0.5 sec, the breakthrough times for odor concentration were D>C>B>A, and the breakthrough times for hydrogen sulfide were D>C>B>A. Effectiveness of activated carbon impregnated iodic acid was recognized. 11 refs., 7 figs., 7 tabs.

Porous structure and surface chemistry of phosphoric acid activated carbon from corncob

International Nuclear Information System (INIS)

Sych, N.V.; Trofymenko, S.I.; Poddubnaya, O.I.; Tsyba, M.M.; Sapsay, V.I.; Klymchuk, D.O.; Puziy, A.M.

2012-01-01

Highlights: ► Phosphoric acid activation results in formation of carbons with acidic surface groups. ► Maximum amount of surface groups is introduced at impregnation ratio 1.25. ► Phosphoric acid activated carbons show high capacity to copper. ► Phosphoric acid activated carbons are predominantly microporous. ► Maximum surface area and pore volume achieved at impregnation ratio 1.0. - Abstract: Active carbons have been prepared from corncob using chemical activation with phosphoric acid at 400 °C using varied ratio of impregnation (RI). Porous structure of carbons was characterized by nitrogen adsorption and scanning electron microscopy. Surface chemistry was studied by IR and potentiometric titration method. It has been shown that porosity development was peaked at RI = 1.0 (S BET = 2081 m 2 /g, V tot = 1.1 cm 3 /g), while maximum amount of acid surface groups was observed at RI = 1.25. Acid surface groups of phosphoric acid activated carbons from corncob includes phosphate and strongly acidic carboxylic (pK = 2.0–2.6), weakly acidic carboxylic (pK = 4.7–5.0), enol/lactone (pK = 6.7–7.4; 8.8–9.4) and phenol (pK = 10.1–10.7). Corncob derived carbons showed high adsorption capacity to copper, especially at low pH. Maximum adsorption of methylene blue and iodine was observed for carbon with most developed porosity (RI = 1.0).

Porous structure and surface chemistry of phosphoric acid activated carbon from corncob

Energy Technology Data Exchange (ETDEWEB)

Sych, N.V.; Trofymenko, S.I.; Poddubnaya, O.I.; Tsyba, M.M. [Institute for Sorption and Endoecology Problems, National Academy of Sciences of Ukraine, 13 General Naumov St., 03164 Kyiv (Ukraine); Sapsay, V.I.; Klymchuk, D.O. [M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, 2 Tereshchenkivska St., 01601 Kyiv (Ukraine); Puziy, A.M., E-mail: alexander.puziy@ispe.kiev.ua [Institute for Sorption and Endoecology Problems, National Academy of Sciences of Ukraine, 13 General Naumov St., 03164 Kyiv (Ukraine)

2012-11-15

Highlights: Black-Right-Pointing-Pointer Phosphoric acid activation results in formation of carbons with acidic surface groups. Black-Right-Pointing-Pointer Maximum amount of surface groups is introduced at impregnation ratio 1.25. Black-Right-Pointing-Pointer Phosphoric acid activated carbons show high capacity to copper. Black-Right-Pointing-Pointer Phosphoric acid activated carbons are predominantly microporous. Black-Right-Pointing-Pointer Maximum surface area and pore volume achieved at impregnation ratio 1.0. - Abstract: Active carbons have been prepared from corncob using chemical activation with phosphoric acid at 400 Degree-Sign C using varied ratio of impregnation (RI). Porous structure of carbons was characterized by nitrogen adsorption and scanning electron microscopy. Surface chemistry was studied by IR and potentiometric titration method. It has been shown that porosity development was peaked at RI = 1.0 (S{sub BET} = 2081 m{sup 2}/g, V{sub tot} = 1.1 cm{sup 3}/g), while maximum amount of acid surface groups was observed at RI = 1.25. Acid surface groups of phosphoric acid activated carbons from corncob includes phosphate and strongly acidic carboxylic (pK = 2.0-2.6), weakly acidic carboxylic (pK = 4.7-5.0), enol/lactone (pK = 6.7-7.4; 8.8-9.4) and phenol (pK = 10.1-10.7). Corncob derived carbons showed high adsorption capacity to copper, especially at low pH. Maximum adsorption of methylene blue and iodine was observed for carbon with most developed porosity (RI = 1.0).

Using raw and sulfur-impregnated activated carbon as active cap for leaching inhibition of mercury and methylmercury from contaminated sediment.

Science.gov (United States)

Ting, Yu; Chen, Chi; Ch'ng, Boon-Lek; Wang, Ying-Lin; Hsi, Hsing-Cheng

2018-07-15

Sulfur-impregnated activated carbon (SAC) has been reported with a high affinity to Hg, but little research has done on understanding its potential as active cap for inhibition of Hg release from contaminated sediments. In this study, high-quality coconut-shell activated carbon (AC) and its derived SAC were examined and shown to have great affinity to both aqueous Hg 2+ and methylmercury (MeHg). SAC had greater partitioning coefficients for Hg 2+ (K D  = 9.42 × 10 4 ) and MeHg (K D  = 7.661 × 10 5 ) as compared to those for AC (K D  = 3.69 × 10 4 and 2.25 × 10 5 , respectively). However, AC appeared to have greater inhibition in total Hg (THg) leaching from sediment (14.2-235.8 mg-Hg/kg-sediment) to porewater phase as compared to SAC. 3 wt% AC amendment in sediment (235.8 mg/kg Hg) was the optimum dosage causing the porewater THg reduction by 99.88%. Moreover, significant inhibition in both THg and MeHg releases within the 83-d trial microcosm tests was demonstrated with active caps composed of SAC + bentonite, SAC + clean sediment, and AC + bentonite. While both AC and SAC successfully reduce the porewater Hg in sediment environment, the smaller inhibition in Hg release by SAC as compared to that by raw AC may suggest that possibly formed HgS nanoparticles could be released into the porewater that elevates the porewater Hg concentration. Copyright © 2018 Elsevier B.V. All rights reserved.

Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC

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A Buasri

2012-11-01

Full Text Available : The continuous production of ethyl ester was studied by using a steady-state fixed bed reactor (FBR. Transesterification of palm stearin (PS and waste cooking palm oil (WCPO with ethanol in the presence of calcium oxide impregnated palm shell activated carbon (CaO/PSAC solid catalyst was investigated. This work was determined the optimum conditions for the production of ethyl ester from PS and WCPO in order to obtain fatty acid ethyl ester (FAEE with the highest yield. The effects of reaction variables such as residence time, ethanol/oil molar ratio, reaction temperature, catalyst bed height and reusability of catalyst in a reactor system on the yield of biodiesel were considered. The optimum conditions were the residence time 2-3 h, ethanol/oil molar ratio 16-20, reaction temperature at 800C, and catalyst bed height 300 mm which yielded 89.46% and 83.32% of the PS and WCPO conversion, respectively. CaO/PSAC could be used repeatedly for 4 times without any activation treatment and no obvious activity loss was observed. It has potential for industrial application in the transesterification of triglyceride (TG. The fuel properties of biodiesel were determined. Keywords: biodiesel, calcium oxide, ethyl ester, fixed bed reactor, palm shell activated carbon

Preparation and characterization of high surface area activated carbon from Fox nut (Euryale ferox shell by chemical activation with H3PO4

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Arvind Kumar

Full Text Available Activated carbons were prepared from Fox nutshell by chemical activation with H3PO4 in N2 atmosphere and their characteristics were studied. The effects of activation temperature and impregnation ratio were examined. N2 adsorption isotherms characterized the surface area, total pore volume, micropore volume and pore size distribution of activated carbons. Activated carbon was produced at 700 °C with a 1.5 impregnation ratio and one hour of activation time has found 2636 m2/g and 1.53 cm3/g of highest BET surface area and total pore volume, respectively. The result of Fourier-infrared spectroscopy analysis of the prepared activated carbon confirmed that the carbon has abundant functional groups on the surface. Field emission scanning electron micrographs of the prepared activated carbon showed that a porous structure formed during activation. Keywords: Activated carbons, Fox nutshell, Chemical activation, H3PO4, Activated carbon, Surface chemistry, Porous structure

Physicochemical properties of carbons prepared from pecan shell by phosphoric acid activation.

Science.gov (United States)

Guo, Yanping; Rockstraw, David A

2007-05-01

Activated carbons were prepared from pecan shell by phosphoric acid activation. The pore structure and acidic surface groups of these carbons were characterized by nitrogen adsorption, Boehm titration and transmittance Fourier infrared spectroscopy (FTIR) techniques. The characterization results demonstrated that the development of pore structure was apparent at temperatures 250 degrees C, and reached 1130m(2)/g and 0.34cm(3)/g, respectively, at 500 degrees C. Impregnation ratio and soaking time at activation temperature also affected the pore development and pore size distribution of final carbon products. At an impregnation ratio of 1.5, activated carbon with BET surface area and micropore volume as high as 861m(2)/g and 0.289cm(3)/g was obtained at 400 degrees C. Microporous activated carbons were obtained in this study. Low impregnation ratio (less than 1.5) and activation temperature (less than 300 degrees C) are favorable to the formation of acidic surface functional groups, which consist of temperature-sensitive (unstable at high temperature) and temperature-insensitive (stable at high temperature) two parts. The disappearance of temperature-sensitive groups was significant at temperature 300 degrees C; while the temperature-insensitive groups are stable even at 500 degrees C. FTIR results showed that the temperature-insensitive part was mostly phosphorus-containing groups as well as some carbonyl-containing groups, while carbonyl-containing groups were the main contributor of temperature-sensitive part.

High surface area microporous activated carbons prepared from Fox nut (Euryale ferox) shell by zinc chloride activation

Energy Technology Data Exchange (ETDEWEB)

Kumar, Arvind; Mohan Jena, Hara, E-mail: hmjena@nitrkl.ac.in

2015-11-30

Graphical abstract: - Highlights: • Activated carbons have been prepared from Fox nutshell with chemical activation using ZnCl{sub 2}. • The thermal behavior of the raw material and impregnated raw material has been carried out by thermogravimetric analysis. • The characterizations of the prepared activated carbons have been determined by nitrogen adsorption–desorption isotherms, FTIR, XRD, and FESEM. • The BET surface area and total pore volume of prepared activated carbon has been obtained as 2869 m{sup 2}/g, 2124 m{sup 2}/g, and 1.96 cm{sup 3}/g, respectively. • The microporous surface area, micropore volume, and microporosity percentage of prepared activated carbon has been obtained as 2124 m{sup 2}/g, 1.68 cm{sup 3}/g, and 85.71%, respectively. - Abstract: High surface area microporous activated carbon has been prepared from Fox nutshell (Euryale ferox) by chemical activation with ZnCl{sub 2} as an activator. The process has been conducted at different impregnation (ZnCl{sub 2}/Fox nutshell) ratios (1–2.5) and carbonization temperatures (500–700 °C). The thermal decomposition behavior of Fox nutshell and impregnated Fox nutshell has been carried out by thermogravimetric analysis. The pore properties including the BET surface area, micropore surface area, micropore volume, and pore size distribution of the activated carbons have been determined by nitrogen adsorption–desorption isotherms at −196 °C using the BET, t-plot method, DR, and BJH methods. The BET surface area, the microporous surface area, total pore volume, and micropore volume have been obtained as 2869 m{sup 2}/g, 2124 m{sup 2}/g, 1.96 cm{sup 3}/g, and 1.68 cm{sup 3}/g, respectively, and the microporosity percentage of the prepared activated carbon is 85.71%. The prepared activated carbons have been also characterized with instrumental methods such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM).

High surface area microporous activated carbons prepared from Fox nut (Euryale ferox) shell by zinc chloride activation

International Nuclear Information System (INIS)

Kumar, Arvind; Mohan Jena, Hara

2015-01-01

Graphical abstract: - Highlights: • Activated carbons have been prepared from Fox nutshell with chemical activation using ZnCl 2 . • The thermal behavior of the raw material and impregnated raw material has been carried out by thermogravimetric analysis. • The characterizations of the prepared activated carbons have been determined by nitrogen adsorption–desorption isotherms, FTIR, XRD, and FESEM. • The BET surface area and total pore volume of prepared activated carbon has been obtained as 2869 m 2 /g, 2124 m 2 /g, and 1.96 cm 3 /g, respectively. • The microporous surface area, micropore volume, and microporosity percentage of prepared activated carbon has been obtained as 2124 m 2 /g, 1.68 cm 3 /g, and 85.71%, respectively. - Abstract: High surface area microporous activated carbon has been prepared from Fox nutshell (Euryale ferox) by chemical activation with ZnCl 2 as an activator. The process has been conducted at different impregnation (ZnCl 2 /Fox nutshell) ratios (1–2.5) and carbonization temperatures (500–700 °C). The thermal decomposition behavior of Fox nutshell and impregnated Fox nutshell has been carried out by thermogravimetric analysis. The pore properties including the BET surface area, micropore surface area, micropore volume, and pore size distribution of the activated carbons have been determined by nitrogen adsorption–desorption isotherms at −196 °C using the BET, t-plot method, DR, and BJH methods. The BET surface area, the microporous surface area, total pore volume, and micropore volume have been obtained as 2869 m 2 /g, 2124 m 2 /g, 1.96 cm 3 /g, and 1.68 cm 3 /g, respectively, and the microporosity percentage of the prepared activated carbon is 85.71%. The prepared activated carbons have been also characterized with instrumental methods such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM).

Synthesis, characterization and performance in arsenic removal of iron-doped activated carbons prepared by impregnation with Fe(III) and Fe(II)

International Nuclear Information System (INIS)

Muniz, G.; Fierro, V.; Celzard, A.; Furdin, G.; Gonzalez-Sanchez, G.; Ballinas, M.L.

2009-01-01

Arsenic removal from natural well water from the state of Chihuahua (Mexico) is investigated by adsorption using a commercial activated carbon (AC). The latter is used as such, or after oxidation by several chemicals in aqueous solution: nitric acid, hydrogen peroxide, and ammonium persulphate. Raw and oxidised activated carbons are fully characterised (elementary analysis, surface chemistry, pore texture parameters, pH ZC , and TEM observation). Adsorption of As is measured in the aforementioned water, containing ca. 300 ppb of arsenic: removal of As is poor with the raw AC, and only the most oxidised carbons exhibit higher performances. By contrast, iron-doped ACs are much more efficient for that purpose, though their As uptake strongly depends on their preparation conditions: a number of samples were synthesised by impregnation of raw and oxidised ACs with HCl aqueous solutions of either FeCl 3 or FeCl 2 at various concentrations and various pH. It is shown that iron(II) chloride is better for obtaining high iron contents in the resultant ACs (up to 8.34 wt.%), leading to high As uptake, close to 0.036 mg As/g C. In these conditions, 100% of the As initially present in the natural well water is removed, as soon as the Fe content of the adsorbent is higher than 2 wt.%.

Adsorption of methyl orange using activated carbon prepared from lignin by ZnCl2 treatment

Science.gov (United States)

Mahmoudi, K.; Hamdi, N.; Kriaa, A.; Srasra, E.

2012-08-01

Lignocellulosic materials are good and cheap precursors for the production of activated carbon. In this study, activated carbons were prepared from the lignin at different temperatures (200 to 500°C) by ZnCl2. The effects influencing the surface area of the resulting activated carbon are activation temperature, activation time and impregnation ratio. The optimum condition, are found an impregnation ratio of 2, an activation temperature of 450°C, and an activation time of 2 h. The results showed that the surface area and micropores volume of activated carbon at the experimental conditions are achieved to 587 and 0.23 cm3 g-1, respectively. The adsorption behavior of methyl orange dye from aqueous solution onto activated lignin was investigated as a function of equilibrium time, pH and concentration. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. A maximum adsorption capacity of 300 mg g-1 of methyl orange by activated carbon was achieved.

Novel Aluminum Oxide-Impregnated Carbon Nanotube Membrane for the Removal of Cadmium from Aqueous Solution

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Ihsanullah

2017-09-01

Full Text Available An aluminum oxide-impregnated carbon nanotube (CNT-Al2O3 membrane was developed via a novel approach and used in the removal of toxic metal cadmium ions, Cd(II. The membrane did not require any binder to hold the carbon nanotubes (CNTs together. Instead, the Al2O3 particles impregnated on the surface of the CNTs were sintered together during heating at 1400 °C. Impregnated CNTs were characterized using XRD, while the CNT-Al2O3 membrane was characterized using scanning electron microscopy (SEM. Water flux, contact angle, and porosity measurements were performed on the membrane prior to the Cd(II ion removal experiment, which was conducted in a specially devised continuous filtration system. The results demonstrated the extreme hydrophilic behavior of the developed membrane, which yielded a high water flux through the membrane. The filtration system removed 84% of the Cd(II ions at pH 7 using CNT membrane with 10% Al2O3 loading. A maximum adsorption capacity of 54 mg/g was predicted by the Langmuir isotherm model for the CNT membrane with 10% Al2O3 loading. This high adsorption capacity indicated that adsorption was the main mechanism involved in the removal of Cd(II ions.

Regeneration of the iodine isotope-exchange efficiency for nuclear-grade activated carbons

International Nuclear Information System (INIS)

Deitz, V.R.

1985-01-01

The removal of radioactive iodine from air flows passing through impregnated activated carbons depends on a minimum of three distinguishable reactions: (1) adsorption on the carbon networks of the activated carbons, (2) iodine isotope exchange with impregnated iodine-127, and (3) chemical combination with impregnated tertiary amines when present. When a carbon is new, all three mechanisms are at peak performance and it is not possible to distinguish among the three reactions by a single measurement; the retention of methyl iodide-127 is usually equal to the retention of methyl iodide-131. After the carbon is placed in service, the three mechanisms of iodine removal are degraded by the contaminants of the air at different rates; the adsorption process degrades faster than the other two. This behavior will be shown by comparisons of methyl iodide-127 and methyl iodide-131 penetration tests. It was found possible to regenerate the iodine isotope-exchange efficiency by reaction with airborne chemical reducing agents with little or no improvement in methyl iodine-127 retention. Examples will be given of the chemical regeneration of carbons after exhaustion with known contaminants as well as for many carbons removed from nuclear power operations. The depth profile of methyl iodide-131 penetration was determined in 2-inch deep layers before and after chemical treatments

A brief review on activated carbon derived from agriculture by-product

Science.gov (United States)

Yahya, Mohd Adib; Mansor, Muhammad Humaidi; Zolkarnaini, Wan Amani Auji Wan; Rusli, Nurul Shahnim; Aminuddin, Anisah; Mohamad, Khalidah; Sabhan, Fatin Aina Mohamad; Atik, Arif Abdallah Aboubaker; Ozair, Lailatun Nazirah

2018-06-01

A brief review focusing on preparation of the activated carbon derived from agriculture by-products is presented. The physical and chemical activation of activated carbon were also reviewed. The effects of various parameters including types of activating agents, temperature, impregnation ratio, were also discussed. The applications of activated carbon from agricultural by products were briefly reviewed. It is provenly evident in this review, the relatively inexpensive and renewable resources of the agricultural waste were found to be effectively being converted into wealth materials.

Sorption Characteristics of Activated Carbon Obtained from Rice Husks by Treatment with Lime

International Nuclear Information System (INIS)

Hnin Nwe Aye; Aye Aye Maw; Nyunt Wynn

2011-12-01

The sorption studies of rice husk char prepared by carbonization and activation with lime, caustic soda and sulphuric acid have been investigated. Prior to impregnation with the lime; on a micro processing scale the pre-carbonization temperature of rice husk were determined by using TG-DTA thermal analysis. The impregnation with chemical was made after carbonization and the impregnated chars were subjected to activation at appropriate temperatures of about 300 C to 500 C depending on the impregnated chars. The physico-chemical properties of the prepared chars were tested by conventional and modern techniques. Sorption capacities with respect to colored dyes were determined for each of the char. These sorption capacities are indicative of the decolorizing nature and the acid or basic nature. The sorption capacities of the prepared chars towards the uptake of metals such as copper, iron, lead and cadmium were also studied and the lime activated char exhibits high adsorptive capacities for all the metals compared to other prepared chars as well as the commercial wood char. The evaluation of the sorption capacities of this chars were made on the basis of Freundlich and Langmuir monolayer coverage equations. Thus, based on batch dosage method and breakthrough flow method, the uptake of the metals were found to be in following order for the lime activated rice husk char; Cu > Fe > Pb > Cd. From this investigation, it can be inferred that a rice husk char impregnated with 20% technical grade CaO has the potential effect to be used as an effective metal adsorbent particularly for the uptake of toxic heavy metals in the secondary stage of water treatment processes.

Batch sorption dynamics and equilibrium for the removal of lead ions from aqueous phase using activated carbon developed from coffee residue activated with zinc chloride.

Science.gov (United States)

Boudrahem, F; Aissani-Benissad, F; Aït-Amar, H

2009-07-01

Lignocellulosic materials are good precursors for the production of activated carbon. In this work, coffee residue has been used as raw material in the preparation of powder activated carbon by the method of chemical activation with zinc chloride for the sorption of Pb(II) from dilute aqueous solutions. The influence of impregnation ratio (ZnCl2/coffee residue) on the physical and chemical properties of the prepared carbons was studied in order to optimize this parameter. The optimum experimental condition for preparing predominantly microporous activated carbons with high pore surface area (890 m2/g) and micropore volume (0.772 cm3/g) is an impregnation ratio of 100%. The developed activated carbon shows substantial capability to sorb lead(II) ions from aqueous solutions and for relative impregnation ratios of 75 and 100%, the maximum uptake is practically the same. Thus, 75% represents the optimal impregnation ratio. Batch experiments were conducted to study the effects of the main parameters such as contact time, initial concentration of Pb(II), solution pH, ionic strength and temperature. The maximum uptake of lead(II) at 25 degrees C was about 63 mg/g of adsorbent at pH 5.8, initial Pb(II) concentration of 10 mg/L, agitation speed of 200 rpm and ionic strength of 0.005 M. The kinetic data were fitted to the models of pseudo-first order and pseudo-second order, and follow closely the pseudo-second order model. Equilibrium sorption isotherms of Pb(II) were analyzed by the Langmuir, Freundlich and Temkin isotherm models. The Freundlich model gives a better fit than the others. Results from this study suggest that activated carbon produced from coffee residue is an effective adsorbent for the removal of lead from aqueous solutions and that ZnCl2 is a suitable activating agent for the preparation of high-porosity carbons.

Arsenic removal using silver-impregnated Prosopis spicigera L ...

African Journals Online (AJOL)

Arsenic removal using silver-impregnated Prosopis spicigera L. wood (PSLW) activated carbon: batch and column studies. ... Arsenic uptake has no regular trend with increasing pH; contains two adsorption maxima, the first adsorption maximum at pH 4.0 and a second adsorption maximum at pH 10.0. The extent of As (III) ...

Carbons prepared from coffee grounds by H{sub 3}PO{sub 4} activation: Characterization and adsorption of methylene blue and Nylosan Red N-2RBL

Energy Technology Data Exchange (ETDEWEB)

Reffas, A. [LCME, Polytech' Savoie, Universite de Savoie, 73376 Le Bourget du Lac Cedex (France); Laboratoire de l' Ingenierie des Procedes, d' Environnement, Departement de Chimie Industrielle, Universite Mentouri, Constantine 25000 (Algeria); Bernardet, V.; David, B.; Reinert, L. [LCME, Polytech' Savoie, Universite de Savoie, 73376 Le Bourget du Lac Cedex (France); Lehocine, M. Bencheikh [Laboratoire de l' Ingenierie des Procedes, d' Environnement, Departement de Chimie Industrielle, Universite Mentouri, Constantine 25000 (Algeria); Dubois, M.; Batisse, N. [LMI, CNRS, Universite Blaise Pascal, 24 Avenue des Landais, 63177 Aubiere Cedex (France); Duclaux, L., E-mail: laurent.duclaux@univ-savoie.fr [LCME, Polytech' Savoie, Universite de Savoie, 73376 Le Bourget du Lac Cedex (France)

2010-03-15

Activated carbons were prepared by the pyrolysis of coffee grounds impregnated by phosphoric acid at 450 deg. C for different impregnation ratios: 30, 60, 120 and 180 wt.%. Materials were characterized for their surface chemistry by elemental analysis, 'Boehm titrations', point of zero charge measurements, Infrared spectroscopy, thermogravimetric analysis (TGA); as well as for their porous and morphological structure by Scanning Electron Microscopy (SEM) and nitrogen adsorption at 77 K. The impregnation ratio was found to govern the porous structure of the prepared activated carbons. Low impregnation ratios (<120 wt.%) led to essentially microporous and acidic activated carbons whereas high impregnation ratios (>120 wt.%) yielded to essentially mesoporous carbons with specific surface areas as high as 925 m{sup 2} g{sup -1}, pore volume as large as 0.7 cm{sup 3} g{sup -1}, and neutral surface. The activated carbons prepared from coffee grounds were compared to a commercial activated carbon (S{sub BET} {approx} 1400 m{sup 2} g{sup -1}) for their adsorption isotherms of methylene blue and 'Nylosan Red N-2RBL', a cationic and anionic (azo) dye respectively. The mesoporous structure of the material produced at 180 wt.% H{sub 3}PO{sub 4} ratio was found to be appropriate for an efficient sorption of the latter azo dye.

Textural and chemical characterizations of adsorbent prepared from palm shell by potassium hydroxide impregnation at different stages.

Science.gov (United States)

Guo, Jia; Lua, Aik Chong

2002-10-15

Preparation and characterization of activated carbon from palm shell, a carbonaceous agricultural solid waste, by potassium hydroxide treatment at different stages were studied. The effects of activation temperature and chemical to sample ratio on the characteristics of the activated carbon were investigated. Fixed-bed adsorption of sulfur dioxide (SO(2)) gas was carried out to evaluate the adsorptive capacity of the samples. Desorption tests were conducted to verify the occurrence of chemisorption due to some surface functional groups or of chemical reaction between SO(2) and KOH. It was found that pre-impregnation of raw palm shell was involved in replacement of some hydrogen ions with potassium ions to form cross-linked complexes, which retarded the tar formation during carbonization, resulting in a relatively high yield. Moreover, these potassium ions accelerated the reaction as catalysts during gasification of chars by carbon dioxide. For chars with mid-impregnation, potassium hydroxide acted in two ways: (i) formation of metallic potassium by dehydration and (ii) conversion into potassium carbonate. Metallic potassium intercalated to the carbon matrix accounted for pore development and potassium carbonate layer prevented the sample from over burn-off. Post-impregnation of final products modified the textural characteristics of the sample as some pore entrances were blocked by chemicals. However, potassium hydroxide enhanced the amount of SO(2) uptaken via formation of potassium sulfite.

Adsorption Studies of Chromium(VI) on Activated Carbon Derived from Mangifera indica (Mango) Seed Shell

Science.gov (United States)

Mise, Shashikant; Patil, Trupti Nagendra

2015-09-01

The removal of chromium(VI) from synthetic sample by adsorption on activated carbon prepared from Mangifera indica (mango) seed shell have been carried out at room temperature 32 ± 1 °C. The removal of chromium(VI) from synthetic sample by adsorption on two types of activated carbon, physical activation and chemical activation (Calcium chloride and Sodium chloride), Impregnation Ratio's (IR) 0.25, 0.50, 0.75 for optimum time, optimum dosages and variation of pH were studied. It is observed that contact time differs for different carbons i.e. for physically and chemically activated carbons. The contact time decreases for chemically activated carbon compared to the physically activated carbon. It was observed that as dosage increases the adsorption increased along with the increase in impregnation ratio. It was also noted that as I.R. increases the surface area of Mangifera indica shell carbon increased. These dosage data were considered in the construction of isotherms and it was found that adsorption obeys Freundlich Isotherm and does not obey Langmuir Isotherm. The maximum removal of chromium (VI) was obtained in highly acidic medium at a pH of 1.50.

Anti-biofilm and cytotoxicity activity of impregnated dressings with silver nanoparticles

International Nuclear Information System (INIS)

Velázquez-Velázquez, Jorge Luis; Santos-Flores, Andrés; Araujo-Meléndez, Javier; Sánchez-Sánchez, Roberto; Velasquillo, Cristina; González, Carmen; Martínez-Castañon, Gabriel; Martinez-Gutierrez, Fidel

2015-01-01

Infections arising from bacterial adhesion and colonization on chronic wounds are a significant healthcare problem. Silver nanoparticles (AgNPs) impregnated in dressing have attracted a great deal of attention as a potential solution. The goal of the present study was to evaluate the anti-biofilm activities of AgNPs impregnated in commercial dressings against Pseudomonas aeruginosa, bacteria isolated of chronic wounds from a hospital patient. The antimicrobial activity of AgNPs was tested within biofilms generated under slow fluid shear conditions using a standard bioreactor. A 2-log reduction in the number of colony-forming units of P. aeruginosa was recorded in the reactor on exposure to dressing impregnated with 250 ppm of AgNPs, diameter 9.3 ± 1.1 nm, and also showed compatibility to mammalian cells (human fibroblasts). Our study suggests that the use of dressings with AgNPs may either prevent or reduce microbial growth in the wound environment, and reducing wound bioburden may improve wound-healing outcomes. - Highlights: • Biological activities of silver nanoparticles for wound-healing purposes • Characterization of the silver nanoparticles impregnated in dressings • Reduction in the P. aeruginosa biofilm formation was statistically significant. • Compatibility to human dermal fibroblasts as the main cell type involved in the reparation • AgNPs covering the surfaces would provide great potential for prevention and treatment

Anti-biofilm and cytotoxicity activity of impregnated dressings with silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Velázquez-Velázquez, Jorge Luis [Laboratorio de Microbiología, Facultad de Ciencias Químicas, UASLP (Mexico); Santos-Flores, Andrés; Araujo-Meléndez, Javier [Servicio de Epidemiología del Hospital Central “Dr. Ignacio Morones Prieto”, San Luis Potosí (Mexico); Sánchez-Sánchez, Roberto; Velasquillo, Cristina [Laboratorio de Biotecnología, Instituto Nacional de Rehabilitación (Mexico); González, Carmen [Laboratorio de Fisiología Celular, Facultad de Ciencias Químicas, UASLP (Mexico); Martínez-Castañon, Gabriel [Maestría en Ciencias Odontológicas Facultad de Estomatología, UASLP (Mexico); Martinez-Gutierrez, Fidel, E-mail: fidel@uaslp.mx [Laboratorio de Microbiología, Facultad de Ciencias Químicas, UASLP (Mexico)

2015-04-01

Infections arising from bacterial adhesion and colonization on chronic wounds are a significant healthcare problem. Silver nanoparticles (AgNPs) impregnated in dressing have attracted a great deal of attention as a potential solution. The goal of the present study was to evaluate the anti-biofilm activities of AgNPs impregnated in commercial dressings against Pseudomonas aeruginosa, bacteria isolated of chronic wounds from a hospital patient. The antimicrobial activity of AgNPs was tested within biofilms generated under slow fluid shear conditions using a standard bioreactor. A 2-log reduction in the number of colony-forming units of P. aeruginosa was recorded in the reactor on exposure to dressing impregnated with 250 ppm of AgNPs, diameter 9.3 ± 1.1 nm, and also showed compatibility to mammalian cells (human fibroblasts). Our study suggests that the use of dressings with AgNPs may either prevent or reduce microbial growth in the wound environment, and reducing wound bioburden may improve wound-healing outcomes. - Highlights: • Biological activities of silver nanoparticles for wound-healing purposes • Characterization of the silver nanoparticles impregnated in dressings • Reduction in the P. aeruginosa biofilm formation was statistically significant. • Compatibility to human dermal fibroblasts as the main cell type involved in the reparation • AgNPs covering the surfaces would provide great potential for prevention and treatment.

Utilization of oil palm fronds in producing activated carbon using Na2CO3 as an activator

Science.gov (United States)

Maulina, S.; Anwari, FN

2018-02-01

Oil Palm Frond is a waste in palm oil plantations that have the potential to be processed into more valuable products. This possibility is because of the presence of cellulose, hemicellulose, and lignin in oil palm fronds. Therefore, this study aimed to utilize oil palm fronds in manufacturing of activated carbon through pyrolysis and impregnation that meets the requirements of the Industrial National Standard 06-3730-1995. The palm-fringed oil palm fronds were pyrolyzed in reactors at 150°C, 200°C, and 250°C for 60 minutes. Subsequently, the charcoal produced from the pyrolysis was smoothed with a ball mill, sieved with a size of 140 meshes, and impregnated using a Sodium Carbonate (Na2CO3) for 24 hours at a concentration of 0 %, 2.5%, 5%, and 7.5 % (w/v). The activated carbon has 35.13% of charcoal yield, 8.6% of water content, 14.25% of ash content, 24.75% of volatile matter, 72.75% of fixed carbon, and 492.29 of iodine number. Moreover, SEM analysis indicated that activated carbon porous are coarse and distributed.

Trickle bed reactor for the oxidation of phenol over active carbon catalyst

OpenAIRE

Gabbiye, Nigus; Font Capafons, Josep; Fortuny Sanromá, Agustín; Bengoa, Christophe José; Fabregat Llangotera, Azael; Stüber, Frank Erich

2009-01-01

The catalytic wet air oxidation of phenol using activated carbon has been performed in a laboratory trickle bed reactor over a wide range of operating variables (PO2, T, FL and Cph,o) and hydrodynamic conditions. The influence of different start-up procedures (saturation of activated carbon) has also been tested. Further improvement of activity and stability has been checked for by using dynamic TBR operation concept or impregnated Fe/carbon catalyst. The results obtained confi...

Removal of Heavy Metal Ions with Acid Activated Carbons Derived from Oil Palm and Coconut Shells

Science.gov (United States)

Rahman, Mokhlesur M.; Adil, Mohd; Yusof, Alias M.; Kamaruzzaman, Yunus B.; Ansary, Rezaul H.

2014-01-01

In this work, batch adsorption experiments were carried out to investigate the suitability of prepared acid activated carbons in removing heavy metal ions such as nickel(II), lead(II) and chromium(VI). Acid activated carbons were obtained from oil palm and coconut shells using phosphoric acid under similar activation process while the differences lie either in impregnation condition or in both pretreatment and impregnation conditions. Prepared activated carbons were modified by dispersing hydrated iron oxide. The adsorption equilibrium data for nickel(II) and lead(II) were obtained from adsorption by the prepared and commercial activated carbons. Langmuir and Freundlich models fit the data well. Prepared activated carbons showed higher adsorption capacity for nickel(II) and lead(II). The removal of chromium(VI) was studied by the prepared acid activated, modified and commercial activated carbons at different pH. The isotherms studies reveal that the prepared activated carbon performs better in low concentration region while the commercial ones in the high concentration region. Thus, a complete adsorption is expected in low concentration by the prepared activated carbon. The kinetics data for Ni(II), Pb(II) and Cr(VI) by the best selected activated carbon fitted very well to the pseudo-second-order kinetic model. PMID:28788640

Removal of Heavy Metal Ions with Acid Activated Carbons Derived from Oil Palm and Coconut Shells

Directory of Open Access Journals (Sweden)

Mokhlesur M. Rahman

2014-05-01

Full Text Available In this work, batch adsorption experiments were carried out to investigate the suitability of prepared acid activated carbons in removing heavy metal ions such as nickel(II, lead(II and chromium(VI. Acid activated carbons were obtained from oil palm and coconut shells using phosphoric acid under similar activation process while the differences lie either in impregnation condition or in both pretreatment and impregnation conditions. Prepared activated carbons were modified by dispersing hydrated iron oxide. The adsorption equilibrium data for nickel(II and lead(II were obtained from adsorption by the prepared and commercial activated carbons. Langmuir and Freundlich models fit the data well. Prepared activated carbons showed higher adsorption capacity for nickel(II and lead(II. The removal of chromium(VI was studied by the prepared acid activated, modified and commercial activated carbons at different pH. The isotherms studies reveal that the prepared activated carbon performs better in low concentration region while the commercial ones in the high concentration region. Thus, a complete adsorption is expected in low concentration by the prepared activated carbon. The kinetics data for Ni(II, Pb(II and Cr(VI by the best selected activated carbon fitted very well to the pseudo-second-order kinetic model.

Characterization and restoration of performance of 'aged' radioiodine removing activated carbons

International Nuclear Information System (INIS)

Freeman, W.P.

1997-01-01

The degradation of radioiodine removal performance for impregnated activated carbons because of ageing is well established. However, the causes for this degradation remain unclear. One theory is that this reduction in performance from the ageing process results from an oxidation of the surface of the carbon. Radioiodine removing activated carbons that failed radioiodine removal tests showed an oxidized surface that had become hydrophilic compared with new carbons. We attempted to restore the performance of these 'failed' carbons with a combination of thermal and chemical treatment. The results of these investigations are presented and discussed with the view of extending the life of radioiodine removing activated carbons. 4 refs., 2 tabs

Study on adsorption performance of coal based activated carbon to radioactive iodine and stable iodine

International Nuclear Information System (INIS)

Zhou, Junbo; Hao, Shan; Gao, Liping; Zhang, Youchen

2014-01-01

Highlights: • The impregnated coal-based activated carbons as adsorbent for removing methyl iodide. • The coal-based activated carbons to remove stable iodine. • Iodine residues are under 0.5 μg/ml after adsorption treatment. • The decontamination factor is much higher than 1000. - Abstract: Nuclear power plant, nuclear reactors and nuclear powered ship exhaust contains a large amount of gaseous radioactive iodine, and can damage to the workplace and the surrounding environment. The quantitative test to remove methyl iodide and the qualitative test for removing stable iodine were investigated using the impregnated coal-based activated carbons and coal-based activated carbons as adsorbents. The research conducted in this work shows that iodine residues were under 0.5 μg/ml after adsorption treatment and the decontamination factor of the coal-based activated carbon for removing the stable iodine was more than 1000, which can achieve the purpose of removing harmful iodine, and satisfy the requirement of gaseous waste treatment of nuclear powered vessel and other nuclear plants

Evaluation of optimal silver amount for the removal of methyl iodide on silver-impregnated adsorbents

International Nuclear Information System (INIS)

Park, G.I.; Cho, I.H.; Kim, J.H.; Oh, W.Z.

2001-01-01

The adsorption characteristics of methyl iodide generated from the simulated off-gas stream on various adsorbents such as silver-impregnated zeolite (AgX), zeocarbon and activated carbon were investigated. An extensive evaluation was made on the optimal silver impregnation amount for the removal of methyl iodide at temperatures up to 300 deg. C. The degree of adsorption efficiency of methyl iodide on silver-impregnated adsorbent is strongly dependent on impregnation amount and process temperature. A quantitative comparison of adsorption efficiencies on three adsorbents in a fixed bed was investigated. The influence of temperature, methyl iodide concentration and silver impregnation amount on the adsorption efficiency is closely related to the pore characteristics of adsorbents. It shows that the effective impregnation ratio was about 10wt%, based on the degree of silver utilization for the removal of methyl iodide. The practical applicability of silver-impregnated zeolite for the removal of radioiodine generated from the DUPIC process was consequently proposed. (author)

Adsorption and photodegradation of methylene blue by iron oxide impregnated on granular activated carbons in an oxalate solution

International Nuclear Information System (INIS)

Kadirova, Zukhra C.; Katsumata, Ken-ichi; Isobe, Toshihiro; Matsushita, Nobuhiro; Nakajima, Akira; Okada, Kiyoshi

2013-01-01

The photocatalytic adsorbents BAU-OA, BAU-CL and BAU-HA with varying iron oxide content (9–10 mass%) were prepared by heat treatment at 250 °C from commercial activated carbon (BAU) impregnated with iron oxalate, chloride, tris-benzohydroxamate, respectively. The XRD patterns showed amorphous structure in the BAU-CL sample (S BET 50 m 2 /g) and low crystallinity (as FeOOH and Fe 2 O 3 phases) in the BAU-HA and BAU-OA samples (S BET 4 and 111 m 2 /g, respectively). The methylene blue adsorption capacities was decreased in order of BAU-OA app ) was increased in same order BAU-HA < BAU-CL < BAU-OA under the standard experimental conditions (initial MB concentrations 0.015–0.025 mM; sample content – 10 mg/l; initial oxalic acid concentration – 0.43 mM; pH 3–4; UV illumination). The process included high efficiency combination of adsorption, heterogeneous and homogeneous catalysis under UV and solar lights illumination without addition of hydrogen peroxide. The detoxification of water sample containing organic dyes was confirmed after combined sorption-photocatalytic treatment.

Separation of yttrium using carbon nanotube doped polymeric beads impregnated with D2EHPA

International Nuclear Information System (INIS)

Dasgupta, Kinshuk; Yadav, Kartikey K.; Singh, D.K.; Anitha, M.; Singh, H.

2013-01-01

Di-2-ethylhexyl phosphoric acid impregnated polyethersulfone based composite beads in combination with additives such as polyvinyl alcohol (PVA) and multiwalled carbon nanotube (MWCNT) has been prepared by non-solvent phase inversion method. The synthesized beads were characterized by scanning electron microscopy, thermogravimetry and infra-red spectroscopy. Effect of additives on bead morphology, solvent impregnation capacity, extractability and stability has been examined to compare their suitability for yttrium recovery from acidic medium. Microstructural investigation as well as experimental findings confirmed the role of additives in modifying the pore structures in beads, responsible for varied degree of yttrium extraction. Further the role of metal ion concentration in aqueous phase on its recovery by polymeric beads was also evaluated. Among the tested beads PES/D2EHPA/MWCNT/PVA beads were found to be superior for Y(Ill) extraction. (author)

Supercritical impregnation of cinnamaldehyde into polylactic acid as a route to develop antibacterial food packaging materials.

Science.gov (United States)

Villegas, Carolina; Torres, Alejandra; Rios, Mauricio; Rojas, Adrián; Romero, Julio; de Dicastillo, Carol López; Valenzuela, Ximena; Galotto, María José; Guarda, Abel

2017-09-01

Supercritical impregnation was used to incorporate a natural compound with antibacterial activity into biopolymer-based films to develop active food packaging materials. Impregnation tests were carried out under two pressure conditions (9 and 12MPa), and three depressurization rates (0.1, 1 and 10MPamin -1 ) in a high-pressure cell at a constant temperature equal to 40°C. Cinnamaldehyde (Ci), a natural compound with proven antimicrobial activity, was successfully incorporated into poly(lactic acid) films (PLA) using supercritical carbon dioxide (scCO 2 ), with impregnation yields ranging from 8 to 13% w/w. Higher pressure and slower depressurization rate seem to favor the Ci impregnation. The incorporation of Ci improved thermal, structural and mechanical properties of the PLA films. Impregnated films were more flexible, less brittle and more resistant materials than neat PLA films. The tested samples showed strong antibacterial activity against the selected microorganisms. In summary, this study provides an innovative route to the development of antibacterial biodegradable materials, which could be used in a wide range of applications of active food packaging. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ferrihydrite-impregnated granular activated carbon (FH@GAC) for efficient phosphorus removal from wastewater secondary effluent.

Science.gov (United States)

Mahardika, Dedy; Park, Hak-Soon; Choo, Kwang-Ho

2018-05-23

Adsorptive removal of phosphorus from wastewater effluents has attracted attention because of its reduced sludge production and potential P recovery. In this study, we investigated granular activated carbons (GACs) impregnated with amorphous ferrihydrite (FH@GAC) for the sorption of phosphorus from aqueous solutions. Preoxidation of intact GAC surfaces using an oxidant (e.g., hypochlorite) and strong acids (e.g., HNO 3 /H 2 SO 4 ) was performed to create active functional groups (e.g., carboxyl or phenolic) for enhanced iron binding, leading to greater phosphorus uptake. Both the rate and the capacity of phosphorus sorption onto FH@GAC had significant, positive relationships (Pearson correlation coefficient r > 0.9) with the product of surface area and Fe content. The pseudo-second-order reaction kinetics explained the P sorption rate better than the pseudo-first-order reaction kinetics, whereas the Langmuir model fit the P sorption isotherm better than the Freundlich model. The iron content in the FH@GAC increased significantly (>10 mg/g) when GAC (e.g., BMC1050) was preoxidized by a 1:1 (w/w) concentrated HNO 3 /H 2 SO 4 mixture. The Langmuir maximum P sorption capacity of a functionalized FH@BMC1050 adsorbent prepared with acid pretreatment was estimated to be substantial (5.73 mg P/g GAC corresponding to 526 mg P/g Fe). This sorption capacity was superior to that of a FH slurry, possibly because the nano-sized FH formed inside the GAC pores (<2.5 nm) can bind phosphate ions more effectively than FH aggregates. Fixed-bed column reactor operation with bicarbonate regeneration showed potential for efficient, continuous phosphorus removal by FH@GAC media. Copyright © 2018 Elsevier Ltd. All rights reserved.

Optimization Of Activated Carbon Preparation From Spent Mushroom Farming Waste (SMFW) Via Box- Behnken Design Of Response Surface Methodology

International Nuclear Information System (INIS)

Nurul Shuhada Md Desa; Zaidi Ab Ghani; Suhaimi Abdul-Talib; Chia-Chay, T.

2016-01-01

This study focuses on activated carbon preparation from spent mushroom farming waste (SMFW) via chemical activation using Box-Behnken design (BBD) of Response Surface Methodology (RSM). Potassium hydroxide (KOH) functions as activating reagent and it play an important role in enhancing the activated carbon porosity. Three input parameters and two responses were evaluated via this software generated experimental design. The effects of three preparation parameters of impregnation ratio, activation time and activation temperature as well as two responses of carbon yield and iodine number were investigated. The optimum conditions for preparing activated carbon from SMFW was found at SMFW: KOH impregnation ratio of 0.25, activation time of 30 min and activation temperature of 400 degree Celsius which resulted in 28.23 % of carbon yield and 314.14 mg/ g of iodine number with desirability of 0.994. The predicted results were well corresponded with experimental results. This study is important in economical large scale SMFW activated carbon preparation for application study of adsorption process for metal treatment in wastewater with minimum chemical and energy input. (author)

Effect of reaction environments on the reactivity of PCB (2-chlorobiphenyl) over activated carbon impregnated with palladized iron

Energy Technology Data Exchange (ETDEWEB)

Choi, Hyeok [Department of Civil Engineering, University of Texas at Arlington, 416 Yates Drive, Arlington, TX 76019-0308 (United States); Al-Abed, Souhail R., E-mail: al-abed.souhail@epa.gov [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, OH 45268 (United States)

2010-07-15

Reactive activated carbon (RAC) impregnated with palladized iron nanoparticles has been developed to treat polychlorinated biphenyls (PCBs). In this study, we evaluated the effects of various reaction environments on the adsorption-mediated dechlorination of 2-chlorobiphenyl (2-ClBP) in the RAC system. The results were discussed in close connection to the implementation issue of the RAC system for the remediation of contaminated sites with PCBs. Adsorption event of 2-ClBP onto RAC limited the overall performance under condition with a 2-ClBP/RAC mass ratio of less than 1.0 x 10{sup -4} above which dechlorination of 2-ClBP adsorbed to RAC was the reaction rate-determining step. Acidic and basic conditions were harmful to 2-ClBP adsorption and iron stability while neutral pH showed the highest adsorption-promoted dechlorination of 2-ClBP and negligible metal leaching. Coexisting natural organic matter (NOM) slightly inhibited 2-ClBP adsorption onto RAC due to the partial partitioning of 2-ClBP into NOM in the liquid phase while the 2-ClBP absorbed into NOM, which also tended to adsorb onto RAC, was less available for the dechlorination reaction. Common anions slowed down 2-ClBP adsorption but adsorbed 2-ClBP was almost simultaneously dechlorinated. Some exceptions included strong inhibitory effect of carbonate species on 2-ClBP adsorption and severe detrimental effect of sulfite on 2-ClBP dechlorination. Results on treatment of 2-ClBP spiked to actual sediment supernatants implied site-specific reactivity of RAC.

Influence of activated carbon characteristics on toluene and hexane adsorption: Application of surface response methodology

Science.gov (United States)

Izquierdo, Mª Teresa; de Yuso, Alicia Martínez; Valenciano, Raquel; Rubio, Begoña; Pino, Mª Rosa

2013-01-01

The objective of this study was to evaluate the adsorption capacity of toluene and hexane over activated carbons prepared according an experimental design, considering as variables the activation temperature, the impregnation ratio and the activation time. The response surface methodology was applied to optimize the adsorption capacity of the carbons regarding the preparation conditions that determine the physicochemical characteristics of the activated carbons. The methodology of preparation produced activated carbons with surface areas and micropore volumes as high as 1128 m2/g and 0.52 cm3/g, respectively. Moreover, the activated carbons exhibit mesoporosity, ranging from 64.6% to 89.1% the percentage of microporosity. The surface chemistry was characterized by TPD, FTIR and acid-base titration obtaining different values of surface groups from the different techniques because the limitation of each technique, but obtaining similar trends for the activated carbons studied. The exhaustive characterization of the activated carbons allows to state that the measured surface area does not explain the adsorption capacity for either toluene or n-hexane. On the other hand, the surface chemistry does not explain the adsorption results either. A compromise between physical and chemical characteristics can be obtained from the appropriate activation conditions, and the response surface methodology gives the optimal activated carbon to maximize adsorption capacity. Low activation temperature, intermediate impregnation ratio lead to high toluene and n-hexane adsorption capacities depending on the activation time, which a determining factor to maximize toluene adsorption.

The Effect of Water Repellent Surface Impregnation on Durability of Cement-Based Materials

Directory of Open Access Journals (Sweden)

Peng Zhang

2017-01-01

Full Text Available In many cases, service life of reinforced concrete structures is severely limited by chloride penetration until the steel reinforcement or by carbonation of the covercrete. Water repellent treatment on the surfaces of cement-based materials has often been considered to protect concrete from these deteriorations. In this paper, three types of water repellent agents have been applied on the surface of concrete specimens. Penetration profiles of silicon resin in treated concrete have been determined by FT-IR spectroscopy. Water capillary suction, chloride penetration, carbonation, and reinforcement corrosion in both surface impregnated and untreated specimens have been measured. Results indicate that surface impregnation reduced the coefficient of capillary suction of concrete substantially. An efficient chloride barrier can be established by deep impregnation. Water repellent surface impregnation by silanes also can make the process of carbonation action slow. In addition, it also has been concluded that surface impregnation can provide effective corrosion protection to reinforcing steel in concrete with migrating chloride. The improvement of durability and extension of service life for reinforced concrete structures, therefore, can be expected through the applications of appropriate water repellent surface impregnation.

In-situ degradation of sulphur mustard and its simulants on the surface of impregnated carbon systems

Energy Technology Data Exchange (ETDEWEB)

Sharma, Abha [Defence Research and Development Establishment, Jhansi Road, Gwalior, MP (India); Saxena, Amit [Defence Research and Development Establishment, Jhansi Road, Gwalior, MP (India); Singh, Beer [Defence Research and Development Establishment, Jhansi Road, Gwalior, MP (India)]. E-mail: beerbs5@rediffmail.com; Sharma, Mamta [Defence Research and Development Establishment, Jhansi Road, Gwalior, MP (India); Suryanarayana, Malladi Venkata Satya [Defence Research and Development Establishment, Jhansi Road, Gwalior, MP (India); Semwal, Rajendra Prasad [Defence Research and Development Establishment, Jhansi Road, Gwalior, MP (India); Ganeshan, Kumaran [Defence Research and Development Establishment, Jhansi Road, Gwalior, MP (India); Sekhar, Krishnamurthy [Defence Research and Development Establishment, Jhansi Road, Gwalior, MP (India)

2006-05-20

Bis-2-chloroethyl sulphide (sulphur mustard or HD) is an extremely toxic and persistent chemical warfare agent. For in situ degradation of HD and its analogues (simulants), i.e., dibutyl sulphide (DBS) and ethyl 2-hydroxyethyl sulphide (HEES), different carbon systems such as 11-molybdo-1-vanadophosphoric acid impregnated carbon (V{sub 1}/C), ruthenium chloride impregnated carbon (Ru/C) and combination of these two (V{sub 1}/Ru/C) were prepared. These carbons were characterized for cumulative micropore volume and surface area by N{sub 2} BET. The kinetics of the in situ degradation of HD and its simulants were studied and found to be following the first order kinetics. Kinetic rate constants and t {sub 1/2} values were determined. Products were characterized using NMR, IR and GC-MS. Reaction products were found to be sulphoxide and sulphone. The combined system, i.e., 11-molybdo-1-vanadophosphoric acid plus ruthenium chloride (V{sub 1}/Ru/C) was found to be best for in-situ degradation of HD and its simulants. In-situ degradation by polyoxometalate based system was found to be stoichiometry based while Ru/C oxidized HD in presence of chemisorbed oxygen. In combined system of V{sub 1}/Ru/C ruthenium worked as a catalyst and polyoxometalate acted as a source of oxygen. Effect of moisture was also studied in combined system. Rate of degradation of HD was found to be increasing with increased percentage of moisture content.

In-situ degradation of sulphur mustard and its simulants on the surface of impregnated carbon systems

International Nuclear Information System (INIS)

Sharma, Abha; Saxena, Amit; Singh, Beer; Sharma, Mamta; Suryanarayana, Malladi Venkata Satya; Semwal, Rajendra Prasad; Ganeshan, Kumaran; Sekhar, Krishnamurthy

2006-01-01

Bis-2-chloroethyl sulphide (sulphur mustard or HD) is an extremely toxic and persistent chemical warfare agent. For in situ degradation of HD and its analogues (simulants), i.e., dibutyl sulphide (DBS) and ethyl 2-hydroxyethyl sulphide (HEES), different carbon systems such as 11-molybdo-1-vanadophosphoric acid impregnated carbon (V 1 /C), ruthenium chloride impregnated carbon (Ru/C) and combination of these two (V 1 /Ru/C) were prepared. These carbons were characterized for cumulative micropore volume and surface area by N 2 BET. The kinetics of the in situ degradation of HD and its simulants were studied and found to be following the first order kinetics. Kinetic rate constants and t 1/2 values were determined. Products were characterized using NMR, IR and GC-MS. Reaction products were found to be sulphoxide and sulphone. The combined system, i.e., 11-molybdo-1-vanadophosphoric acid plus ruthenium chloride (V 1 /Ru/C) was found to be best for in-situ degradation of HD and its simulants. In-situ degradation by polyoxometalate based system was found to be stoichiometry based while Ru/C oxidized HD in presence of chemisorbed oxygen. In combined system of V 1 /Ru/C ruthenium worked as a catalyst and polyoxometalate acted as a source of oxygen. Effect of moisture was also studied in combined system. Rate of degradation of HD was found to be increasing with increased percentage of moisture content

Preparation and characterization of activated carbon from reedy grass leaves by chemical activation with H{sub 3}PO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Xu, Jianzhong, E-mail: xjz8112@sina.com [College of Chemistry and Environmental Science, Hebei University, Baoding 071002, Hebei (China); Chen, Lingzhi [College of Chemistry and Environmental Science, Hebei University, Baoding 071002, Hebei (China); Department of Applied Chemistry, Hengshui University, Hengshui 053000, Hebei (China); Qu, Hongqiang; Jiao, Yunhong; Xie, Jixing [College of Chemistry and Environmental Science, Hebei University, Baoding 071002, Hebei (China); Xing, Guangen [Department of Applied Chemistry, Hengshui University, Hengshui 053000, Hebei (China)

2014-11-30

Highlights: • Activated carbons were produced from reedy grass leaves by activation with phosphoric acid. • The activated carbons have a large number of oxygen- and phosphorus-containing surface groups. • The structure of activated carbons was bight fibers features on the surface and the external surface of the activated carbons was slightly corrugated and abundant pores. - Abstract: Activated carbons were produced from reedy grass leaves by chemical activation with H{sub 3}PO{sub 4} in N{sub 2} atmosphere and their characteristics were investigated. The effects of activation temperature and time were examined. Adsorption capacity was demonstrated with BET and iodine number. Micropore volume and pore size distribution of activated carbons were characterized by N{sub 2} adsorption isotherms. The surface area and iodine number of the activated carbons produced at 500 °C for 2 h were 1474 m{sup 2}/g and 1128 mg/g, respectively. Thermal decomposition of pure reedy grass leaves and H{sub 3}PO{sub 4}-impregnated reedy grass leaves have been investigated with thermogravimetric/mass spectroscopy (TG–MS) technique. It was found that the temperature and intensity of maximum evolution of H{sub 2}O and CO{sub 2} of H{sub 3}PO{sub 4}-impregnated reedy grass leaves were lower than that of pure reedy grass leaves. This implies that H{sub 3}PO{sub 4} as an activating reagent changed the thermal degradation of the reedy grass leaves, stabilized the cellulose structure, leading to a subsequent change in the evolution of porosity. The results of X-ray photoelectron spectroscopy and Fourier-infrared spectroscopy analysis indicate that the produced activated carbons have rich functional groups on surface.

Reinforced Carbon Carbon (RCC) oxidation resistant material samples - Baseline coated, and baseline coated with tetraethyl orthosilicate (TEOS) impregnation

Science.gov (United States)

Gantz, E. E.

1977-01-01

Reinforced carbon-carbon material specimens were machined from 19 and 33 ply flat panels which were fabricated and processed in accordance with the specifications and procedures accepted for the fabrication and processing of the leading edge structural subsystem (LESS) elements for the space shuttle orbiter. The specimens were then baseline coated and tetraethyl orthosilicate impregnated, as applicable, in accordance with the procedures and requirements of the appropriate LESS production specifications. Three heater bars were ATJ graphite silicon carbide coated with the Vought 'pack cementation' coating process, and three were stackpole grade 2020 graphite silicon carbide coated with the chemical vapor deposition process utilized by Vought in coating the LESS shell development program entry heater elements. Nondestructive test results are reported.

Adsorption and photodegradation of methylene blue by iron oxide impregnated on granular activated carbons in an oxalate solution

Energy Technology Data Exchange (ETDEWEB)

Kadirova, Zukhra C., E-mail: zuhra_kadirova@yahoo.com [Institute of General and Inorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Mirzo Ulugbek Str. 77a, Tashkent 100170 (Uzbekistan); Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan); Katsumata, Ken-ichi [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan); Isobe, Toshihiro [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8552 (Japan); Matsushita, Nobuhiro [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan); Nakajima, Akira [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8552 (Japan); Okada, Kiyoshi [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan)

2013-11-01

The photocatalytic adsorbents BAU-OA, BAU-CL and BAU-HA with varying iron oxide content (9–10 mass%) were prepared by heat treatment at 250 °C from commercial activated carbon (BAU) impregnated with iron oxalate, chloride, tris-benzohydroxamate, respectively. The XRD patterns showed amorphous structure in the BAU-CL sample (S{sub BET} 50 m{sup 2}/g) and low crystallinity (as FeOOH and Fe{sub 2}O{sub 3} phases) in the BAU-HA and BAU-OA samples (S{sub BET} 4 and 111 m{sup 2}/g, respectively). The methylene blue adsorption capacities was decreased in order of BAU-OA < BAU-CL < BAU-HA sample and the adsorption followed Langmuir model. The apparent MB photodegradation rate constant (k{sub app}) was increased in same order BAU-HA < BAU-CL < BAU-OA under the standard experimental conditions (initial MB concentrations 0.015–0.025 mM; sample content – 10 mg/l; initial oxalic acid concentration – 0.43 mM; pH 3–4; UV illumination). The process included high efficiency combination of adsorption, heterogeneous and homogeneous catalysis under UV and solar lights illumination without addition of hydrogen peroxide. The detoxification of water sample containing organic dyes was confirmed after combined sorption-photocatalytic treatment.

Aluminum-carbon composite electrode

Science.gov (United States)

Farahmandi, C. Joseph; Dispennette, John M.

1998-07-07

A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

Efficiency of moso bamboo charcoal and activated carbon for adsorbing radioactive iodine

Energy Technology Data Exchange (ETDEWEB)

Chien, Chuan-Chi; Huang, Ying-Pin; Wang, Wie-Chieh [ITRI South, Industrial Technology Research Institute, Tainan (China); Chao, Jun-Hsing; Wei, Yuan-Yao [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu (China)

2011-02-15

Preventing radioactive pollution is a troublesome problem but an urgent concern worldwide because radioactive substances cause serious health-related hazards to human being. The adsorption method has been used for many years to concentrate and remove radioactive pollutants; selecting an adequate adsorbent is the key to the success of an adsorption-based pollution abatement system. In Taiwan, all nuclear power plants use activated carbon as the adsorbent to treat radiation-contaminated air emission. The activated carbon is entirely imported; its price and manufacturing technology are entirely controlled by international companies. Taiwan is rich in bamboo, which is one of the raw materials for high-quality activated carbon. Thus, a less costly activated carbon with the same or even better adsorptive capability as the imported adsorbent can be made from bamboo. The objective of this research is to confirm the adsorptive characteristics and efficiency of the activated carbon made of Taiwan native bamboo for removing {sup 131}I gas from air in the laboratory. The study was conducted using new activated carbon module assembled for treating {sup 131}I-contaminated air. The laboratory results reveal that the {sup 131}I removal efficiency for a single-pass module is as high as 70%, and the overall efficiency is 100% for four single-pass modules operated in series. The bamboo charcoal and bamboo activated carbon have suitable functional groups for adsorbing {sup 131}I and they have greater adsorption capacities than commercial activated carbons. Main mechanism is for trapping of radioiodine on impregnated charcoal, as a result of surface oxidation. When volatile radioiodine is trapped by potassium iodide-impregnated bamboo charcoal, the iodo-compound is first adsorbed on the charcoal surface, and then migrates to iodide ion sites where isotope exchange occurs. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Synthesis and characterization of chemically activated carbon derived from arecanut shell

Directory of Open Access Journals (Sweden)

A. S. Jadhav

2016-03-01

Full Text Available Activated carbon (AC was prepared from areca-nut shell (AS by chemical activation using phosphoric acid (PA. Activated carbon was prepared in three batches using phosphoric acid of 50 gm, 100 gm, and 300 gm with varying impregnation ratios by weight of 1:1, 2:1 and 3:1, 4:1 each. Characterization of the prepared activated carbon was done by methylene blue number (MBN, iodine number (IN, acid adsorption test (AAT, and elemental composition. Activation was carried out at 400 C. It was found that activated carbon derived from areca-nut shell shown improved results for methylene blue number (MBN, iodine number (IN, and acid adsorption test(AAT. Thermal analysis was carried out to know the weight loss and SEM was performed to know the morphology of AC.

Effect of preconditioning on silver leaching and bromide removal properties of silver-impregnated activated carbon (SIAC).

Science.gov (United States)

Rajaeian, Babak; Allard, Sébastien; Joll, Cynthia; Heitz, Anna

2018-07-01

Silver impregnated activated carbon (SIAC) has been found to be effective in mitigating the formation of brominated-disinfection by products during drinking water treatment. However, there are still uncertainties regarding its silver leaching properties, and strategies for the prevention of silver leaching have remained elusive. This study focused on the evaluation of one type of commercially available SIAC for its ability to remove bromide while minimising silver leaching from the material. Both synthetic and real water matrices were tested. Depending on solution pH, it was found that changing the surface charge properties of SIAC, as measured by the point of zero charge pH, can result in additional bromide removal while minimising the extent of silver leaching. To better understand the mechanism of silver leaching from the SIAC, eight preconditioning environments, i.e. variable pH and ionic strength were tested for a fixed amount of SIAC and two preconditioning environments were selected for a more detailed investigation. Experiments carried out in synthetic water showed that preconditioning at pH 10.4 did not deteriorate the capacity of SIAC to remove bromide, but significantly decreased the release of silver in the form of ionic silver (Ag + ), silver bromide (AgBr) and silver chloride (AgCl) from 40% for the pristine to 3% for the treated SIAC. This was confirmed using a groundwater sample. These results suggest that preconditioned SIAC has the potential to be an effective method for bromide removal with minimised silver leaching in a long-term field application for drinking water production. Copyright © 2018 Elsevier Ltd. All rights reserved.

Activated carbon supported CaO for conversion of palm oil to ...

African Journals Online (AJOL)

In this study, activated carbon supported CaO catalyst was used for the transesterification reaction of palm oil. The catalyst was prepared according to the conventional incipient witness impregnation method. Kinetic experiment was performed in a batch reactor in the presence of heterogeneous catalyst for a wide range of ...

Adsorption of Arsenate by Nano Scaled Activated Carbon Modified by Iron and Manganese Oxides

Directory of Open Access Journals (Sweden)

George P. Gallios

2017-09-01

Full Text Available The presence of arsenic in water supplies is a major problem for public health and still concerns large parts of population in Southeast Asia, Latin America and Europe. Removal of arsenic is usually accomplished either by coagulation with iron salts or by adsorption with iron oxides or activated alumina. However, these materials, although very efficient for arsenic, normally do not remove other undesirable constituents from waters, such as chlorine and organo-chlorine compounds, which are the results of water chlorination. Activated carbon has this affinity for organic compounds, but does not remove arsenic efficiently. Therefore, in the present study, iron modified activated carbons are investigated as alternative sorbents for the removal of arsenic(V from aqueous solutions. In addition, modified activated carbons with magnetic properties can easily be separated from the solutions. In the present study, a simple and efficient method was used for the preparation of magnetic Fe3(Mn2+O4 (M:Fe and/or Mn activated carbons. Activated carbons were impregnated with magnetic precursor solutions and then calcinated at 400 °C. The obtained carbons were characterized by X-ray diffraction (XRD, nitrogen adsorption isotherms, scanning electron microscopy (SEM, vibrating sample magnetometer (VSM, Fourier Transform Infrared Spectrometry (FTIR and X-ray photoelectron spectroscopy (XPS measurements. Their adsorption performance for As(V was evaluated. The iron impregnation presented an increase in As(V maximum adsorption capacity (Qmax from about 4 mg g−1 for the raw carbon to 11.05 mg g−1, while Mn incorporation further increased the adsorption capacity at 19.35 mg g−1.

Study of Activated Carbons by Pyrolysis of Mangifera Indica Seed (Mango in Presence of Sodium and Potassium Hydroxide

Directory of Open Access Journals (Sweden)

J. C. Moreno-Piraján

2012-01-01

Full Text Available Activated carbons (ACs were prepared by pyrolysis of seeds mango in presence of sodium and potassium hydroxide (chemical activities. Seeds mango from Colombian Mango cultives were impregnated with aqueous solutions of NaOH and KOH following a variant of the incipient wetness method. Different concentrations were used to produce impregnation ratios of 3:1 (weight terms. Activation was carried out under argon flow by heating to 823 K with 1 h soaking time. The porous texture of the obtained ACs was characterized by physical adsorptions of N2 at 77 K and CO2 at 273 K. The impregnation ration and hydroxide type had a strong influence on the pore structure of these ACs, which could be easily controlled by simply varying the proportion of the hydroxides used in the activation. Thus, the development of porosity for precursors with low structural order (high reactivity is better with NaOH than KOH, whereas the opposite is observed for the highly ordered ones. Variable adsorption capacities and porosity distributions can be achieved depending on the activating agent selected. In general, KOH produces activated carbons with narrower micropore distributions than those prepared by NaOH.

Bactericidal efficacy of silver impregnated activated carbon for disinfection of water

International Nuclear Information System (INIS)

Sultana, L.; Khan, F.A.; Usmani, T.H.

2009-01-01

When highly contaminated water was passed through two types of silver coated activated carbon and their mixtures with sand, the former was found to be far better medium for disinfection of water, with bactericidal efficacy of about 2.5 times that of the latter. (author)

Preparation of activated carbon from Tunisian olive-waste cakes and its application for adsorption of heavy metal ions

International Nuclear Information System (INIS)

Baccar, R.; Bouzid, J.; Feki, M.; Montiel, A.

2009-01-01

The present work explored the use of Tunisian olive-waste cakes, a by-product of the manufacture process of olive oil in mills, as a potential feedstock for the preparation of activated carbon. Chemical activation of this precursor, using phosphoric acid as dehydrating agent, was adopted. To optimize the preparation method, the effect of the main process parameters (such as acid concentration, impregnation ratio, temperature of pyrolysis step) on the performances of the obtained activated carbons (expressed in terms of iodine and methylene blue numbers and specific surface area) was studied. The optimal activated carbon was fully characterized considering its adsorption properties as well as its chemical structure and morphology. To enhance the adsorption capacity of this carbon for heavy metals, a modification of the chemical characteristics of the sorbent surface was performed, using KMnO 4 as oxidant. The efficiency of this treatment was evaluated considering the adsorption of Cu 2+ ions as a model for metallic species. Column adsorption tests showed the high capacity of the activated carbon to reduce KMnO 4 into insoluble manganese (IV) oxide (MnO 2 ) which impregnated the sorbent surface. The results indicated also that copper uptake capacity was enhanced by a factor of up to 3 for the permanganate-treated activated carbon

Preparation of activated carbon from Tunisian olive-waste cakes and its application for adsorption of heavy metal ions

Energy Technology Data Exchange (ETDEWEB)

Baccar, R. [Laboratoire Eau Energie Environnement, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038 Sfax (Tunisia)], E-mail: rym.baccar@tunet.tn; Bouzid, J. [Laboratoire Eau Energie Environnement, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038 Sfax (Tunisia)], E-mail: jalel.bouzid@tunet.tn; Feki, M. [Unite de Recherche de Chimie Industrielle et Materiaux, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038 Sfax (Tunisia)], E-mail: mongi.feki@yahoo.fr; Montiel, A. [Laboratoire Eau Energie Environnement, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038 Sfax (Tunisia)], E-mail: montiel.antoine@free.fr

2009-03-15

The present work explored the use of Tunisian olive-waste cakes, a by-product of the manufacture process of olive oil in mills, as a potential feedstock for the preparation of activated carbon. Chemical activation of this precursor, using phosphoric acid as dehydrating agent, was adopted. To optimize the preparation method, the effect of the main process parameters (such as acid concentration, impregnation ratio, temperature of pyrolysis step) on the performances of the obtained activated carbons (expressed in terms of iodine and methylene blue numbers and specific surface area) was studied. The optimal activated carbon was fully characterized considering its adsorption properties as well as its chemical structure and morphology. To enhance the adsorption capacity of this carbon for heavy metals, a modification of the chemical characteristics of the sorbent surface was performed, using KMnO{sub 4} as oxidant. The efficiency of this treatment was evaluated considering the adsorption of Cu{sup 2+} ions as a model for metallic species. Column adsorption tests showed the high capacity of the activated carbon to reduce KMnO{sub 4} into insoluble manganese (IV) oxide (MnO{sub 2}) which impregnated the sorbent surface. The results indicated also that copper uptake capacity was enhanced by a factor of up to 3 for the permanganate-treated activated carbon.

Catalytic Growth of Macroscopic Carbon Nanofibers Bodies with Activated Carbon

Science.gov (United States)

Abdullah, N.; Rinaldi, A.; Muhammad, I. S.; Hamid, S. B. Abd.; Su, D. S.; Schlogl, R.

2009-06-01

Carbon-carbon composite of activated carbon and carbon nanofibers have been synthesized by growing Carbon nanofiber (CNF) on Palm shell-based Activated carbon (AC) with Ni catalyst. The composites are in an agglomerated shape due to the entanglement of the defective CNF between the AC particles forming a macroscopic body. The macroscopic size will allow the composite to be used as a stabile catalyst support and liquid adsorbent. The preparation of CNT/AC nanocarbon was initiated by pre-treating the activated carbon with nitric acid, followed by impregnation of 1 wt% loading of nickel (II) nitrate solutions in acetone. The catalyst precursor was calcined and reduced at 300° C for an hour in each step. The catalytic growth of nanocarbon in C2H4/H2 was carried out at temperature of 550° C for 2 hrs with different rotating angle in the fluidization system. SEM and N2 isotherms show the level of agglomeration which is a function of growth density and fluidization of the system. The effect of fluidization by rotating the reactor during growth with different speed give a significant impact on the agglomeration of the final CNF/AC composite and thus the amount of CNFs produced. The macrostructure body produced in this work of CNF/AC composite will have advantages in the adsorbent and catalyst support application, due to the mechanical and chemical properties of the material.

A kinetic study of pyrolysis in pitch impregnated electrodes

Energy Technology Data Exchange (ETDEWEB)

Kocaefe, D.; Charette, A.; Ferland, J.; Couderc, P.; Saint-Romain, J.L. (Universite du Quebec a Chicoutini, Chicoutini, PQ (Canada))

1990-12-01

A study was conducted on carbon electrodes which were impregnated with three different pitches. The focus of the study was to investigate the pyrolysis of pitch impregnated electrodes. For the purposes of the research an experimental technique and calculation procedure were developed. A kinetic model was used to interpret the data, comparison of model predictions and experimental data showed good agreement. 17 refs., 10 figs., 2 tabs.

Fe-Impregnated Mineral Colloids for Peroxide Activation: Effects of Mineral Substrate and Fe Precursor.

Science.gov (United States)

Li, Yue; Machala, Libor; Yan, Weile

2016-02-02

Heterogeneous iron species at the mineral/water interface are important catalysts for the generation of reactive oxygen species at circumneutral pH. One significant pathway leading to the formation of such species arises from deposition of dissolved iron onto mineral colloids due to changes in redox conditions. This study investigates the catalytic properties of Fe impregnated on silica, alumina, and titania nanoparticles (as prototypical mineral colloids). Fe impregnation was carried out by immersing the mineral nanoparticles in dilute Fe(II) or Fe(III) solutions at pH 6 and 3, respectively, in an aerobic environment. The uptake of iron per unit surface area follows the order of nTiO2 > nAl2O3 > nSiO2 for both types of Fe precursors. Impregnation of mineral particles in Fe(II) solutions results in predominantly Fe(III) species due to efficient surface-mediated oxidation. The catalytic activity of the impregnated solids to produce hydroxyl radical (·OH) from H2O2 decomposition was evaluated using benzoic acid as a probe compound under dark conditions. Invariably, the rates of benzoic acid oxidation with different Fe-laden particles increase with the surface density of Fe until a critical density above which the catalytic activity approaches a plateau, suggesting active Fe species are formed predominantly at low surface loadings. The critical surface density of Fe varies with the mineral substrate as well as the aqueous Fe precursor. Fe impregnated on TiO2 exhibits markedly higher activity than its Al2O3 and SiO2 counterparts. The speciation of interfacial Fe is analyzed with diffuse reflectance UV-vis analysis and interpretation of the data in the context of benzoic oxidation rates suggests that the surface activity of the solids for ·OH generation correlates strongly with the isolated (i.e., mononuclear) Fe species. Therefore, iron dispersed on mineral colloids is a significant form of reactive iron surfaces in the aquatic environment.

Oil-Impregnated Polyethylene Films

Science.gov (United States)

Mukherjee, Ranit; Habibi, Mohammad; Rashed, Ziad; Berbert, Otacilio; Shi, Shawn; Boreyko, Jonathan

2017-11-01

Slippery liquid-infused porous surfaces (SLIPS) minimize the contact angle hysteresis of a wide range of liquids and aqueous food products. Although hydrophobic polymers are often used as the porous substrate for SLIPS, the choice of polymer has been limited to silicone-based or fluorine-based materials. Hydrocarbon-based polymers, such as polyethylene, are cost effective and widely used in food packaging applications where SLIPS would be highly desirable. However, to date there have been no reports on using polyethylene as a SLIPS substrate, as it is considered highly impermeable. Here, we show that thin films of low-density polyethylene can be stably impregnated with carbon-based oils without requiring any surface modification. Wicking tests reveal that oils with sufficient chemical compatibility follow Washburn's equation. The nanometric effective pore size of the polyethylene does result in a very low wicking speed, but by using micro-thin films and a drawdown coater, impregnation can still be completed in under one second. The oil-impregnated polyethylene films promoted ultra-slippery behavior for water, ketchup, and yogurt while remaining durable even after being submerged in ketchup for over one month. This work was supported by Bemis North America (AT-23981).

Controlled synthesis of carbon-supported Pt{sub 3}Sn by impregnation-reduction and performance on the electrooxidation of CO and ethanol

Energy Technology Data Exchange (ETDEWEB)

Garcia-Rodriguez, S.; Pena, M.A.; Fierro, J.L.G.; Rojas, S. [Grupo Energia y Quimica Sostenibles, Instituto de Catalisis y Petroleoquimica, CSIC, C/Marie Curie 2, E-28049 Madrid (Spain)

2010-09-01

The paper discusses experimental features relevant to the synthesis of carbon-supported Pt{sub 3}Sn nanosized particles by impregnation-reduction of the salt precursors in carbon. Colloidal techniques are proposed as the most suitable ones for obtaining carbon-supported nanosized Pt{sub 3}Sn particles. In most cases, the electrocatalysts obtained have a wide range of Pt and Sn phases, including bimetallic ones. The synthesis of similar materials by impregnating readily available precursors such as SnCl{sub 2} and H{sub 2}PtCl{sub 6} yields Pt-enriched catalyst precursors. In order to obtain electrocatalysts with the desired Pt:Sn = 3 atomic stoichiometry, it is necessary to eliminate chloride ions prior to thermal treatments. Microscopy characterization and thermal stability studies of the fresh and treated bimetallic materials reveal that if such ions are present, Sn is eliminated as volatile SnCl{sub x} species at around 120-130 C. Chloride elimination is achieved by ageing the catalyst precursor in water to ensure the complete hydrolysis of the SnCl{sub 2} precursor. This treatment should be performed once SnCl{sub 2} has been deposited on the carbon to avoid the formation of large Sn-oxide aggregates. A further thermal treatment in hydrogen results in the formation of the desired Pt{sub 3}Sn intermetallic phase. The performance of the Pt{sub 3}Sn/C samples in the CO and ethanol electrooxidation reaction has been studied by means of electrochemical techniques. The electrocatalysts prepared by the impregnation-reduction approach match the performance of the state-of-the-art Pt{sub 3}Sn samples prepared by colloidal techniques. (author)

Polymer-filled microcontainers for oral delivery loaded using supercritical impregnation

DEFF Research Database (Denmark)

Marizza, Paolo; Keller, Stephan Sylvest; Müllertz, Anette

2014-01-01

with a quasi-no-waste performance. Then ketoprofen is impregnated in the polymer matrix by using supercritical carbon dioxide (scCO2) as loading medium. The amount of polymer is controlled by the volume and the number of droplets of dispensed polymer and drug loading is tuned by varying the impregnation...... procedures. This work proposes an effective loading technique for a poorly soluble model drug in microcontainers, by combining inkjet printing and supercritical fluid impregnation. Well defined quantities of poly(vinyl pyrrolidone) (PVP) solutions are dispensed into microcontainers by inkjet printing...

Chromium oxide over activated carbons as catalyst for oxidative dehydrogenation of isobutane

International Nuclear Information System (INIS)

Cardenas, Agobardo; Acero Fabio N; Diaz, Jose de J

2007-01-01

The functional groups at the surface of an activated carbon Norit ROX 08 were modified through reaction with nitric acid, 8.8% 0 2 in N 2 and H 2 . the modified carbons were impregnated with a CrO 3 aqueous solution and used in the oxidative dehydrogenation of isobutane to isobutene (ODH). The formation of isobutene was observed at 443 k, with a maximum selectivity of 85% and a yield of 9%

Characterization and restoration of performance of {open_quotes}aged{close_quotes} radioiodine removing activated carbons

Energy Technology Data Exchange (ETDEWEB)

Freeman, W.P. [NUCON International, Inc., Columbus, OH (United States)

1997-08-01

The degradation of radioiodine removal performance for impregnated activated carbons because of ageing is well established. However, the causes for this degradation remain unclear. One theory is that this reduction in performance from the ageing process results from an oxidation of the surface of the carbon. Radioiodine removing activated carbons that failed radioiodine removal tests showed an oxidized surface that had become hydrophilic compared with new carbons. We attempted to restore the performance of these {open_quotes}failed{close_quotes} carbons with a combination of thermal and chemical treatment. The results of these investigations are presented and discussed with the view of extending the life of radioiodine removing activated carbons. 4 refs., 2 tabs.

Functioned silver nanoparticle loaded activated carbon for the recovery of bioactive molecule from bacterial fermenter for its bactericidal activity

Science.gov (United States)

Arivizhivendhan, Villalan; Mahesh, Mannacharaju; Boopathy, Ramasamy; Karthikeyan, Sekar; Mary, Rathanasamy Regina; Sekaran, Ganesan

2018-01-01

A novel continuous production and extraction of bacterial bioactive prodigiosin (PG) from fermented using silver nanoparticle impregnated functioned activated carbon composite is proposed for cost-effective and ecofriendly microbial technique. Hence, in this investigation silver nanoparticle was impregnated onto functioned activated carbon ([AC]F) as a support matrix and to enable the separation of PG conjugated silver nanoparticle from the fermented medium. A laboratory scale experiment was carried out to evaluate the continuous production and recovery of PG using [AC@Ag]F. Ag nanoparticle impregnated [AC]F ([AC@Ag]F) characterized by FT-IR, XRD, TGA, DSC and SEM. Instrumental analyses confirmed that Ag nanoparticles significantly impregnated on AC through the functionalization of AC with diethanolamine and it enhances the binding capacity between AC and Ag. The various process parameters, such as contact time, pH, and mass of [AC@Ag]F, were statistically optimized for the recovery of PG using Response Surface Methodology (RSM). The maximum extraction of PG in [AC@Ag]F was found to be 16.2 ± 0.2 mg g-1, its twofold higher than [AC]F. Further, PG conjugated [AC@Ag]F and ([AC@Ag]F-PG) were checked for the growth inhibition of gram negative and gram positive bacteria without formation of biofilm upto 96 h. Hence, the developed matrix could be eco-friendly, viable and lower energy consumption step for separation of the bacterial bioactive PG from fermented broth. In additionally, [AC@Ag]F-PG was used as an antifouling matrix without formation of biofilm.

Photocatalytic Activity and Characterization of Carbon-Modified Titania for Visible-Light-Active Photodegradation of Nitrogen Oxides

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Chun-Hung Huang

2012-01-01

Full Text Available A variety of carbon-modified titania powders were prepared by impregnation method using a commercial available titania powder, Hombikat UV100, as matrix material while a range of alcohols from propanol to hexanol were used as precursors of carbon sources. Rising the carbon number of alcoholic precursor molecule, the modified titania showed increasing visible activities of NOx photodegradation. The catalyst modified with cyclohexanol exhibited the best activities of 62%, 62%, 59%, and 54% for the total NOx removal under UV, blue, green, and red light irradiation, respectively. The high activity with long wavelength irradiation suggested a good capability of photocatalysis in full visible light spectrum. Analysis of UV-visible spectrum indicated that carbon modification promoted visible light absorption and red shift in band gap. XPS spectroscopic analysis identified the existence of carbonate species (C=O, which increased with the increasing carbon number of precursor molecule. Photoluminescence spectra demonstrated that the carbonate species suppressed the recombination rate of electron-hole pair. As a result, a mechanism of visible-light-active photocatalyst was proposed according to the formation of carbonate species on carbon-modified TiO2.

High temperature hydrogen sulfide adsorption on activated carbon - I. Effects of gas composition and metal addition

Science.gov (United States)

Cal, M.P.; Strickler, B.W.; Lizzio, A.A.

2000-01-01

Various types of activated carbon sorbents were evaluated for their ability to remove H2S from a simulated coal gas stream at a temperature of 550 ??C. The ability of activated carbon to remove H2S at elevated temperature was examined as a function of carbon surface chemistry (oxidation, thermal desorption, and metal addition), and gas composition. A sorbent prepared by steam activation, HNO3 oxidation and impregnated with Zn, and tested in a gas stream containing 0.5% H2S, 50% CO2 and 49.5% N2, had the greatest H2S adsorption capacity. Addition of H2, CO, and H2O to the inlet gas stream reduced H2S breakthrough time and H2S adsorption capacity. A Zn impregnated activated carbon, when tested using a simulated coal gas containing 0.5% H2S, 49.5% N2, 13% H2, 8.5% H2O, 21% CO, and 7.5% CO2, had a breakthrough time of 75 min, which was less than 25 percent of the length of breakthrough for screening experiments performed with a simplified gas mixture of 0.5% H2S, 50% CO2, and 49.5% N2.

Developing low-cost carbon-based sorbents for Hg capture from flue gas

Energy Technology Data Exchange (ETDEWEB)

Perry, R.; Lakatos, J.; Snape, C.E.; Sun, C. [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre

2005-07-01

To help reduce the cost of Hg capture from flue gas a number of low-cost carbons are being investigated, including activated tyre char and PFA carbon, in conjunction with some of the pre-treatments that have been found to be effective for commercial actived carbons. Experimental conditions for screening the sorbents have been selected to determine breakthrough capacities rapidly. The unactivated carbons have low breakthrough capacities under the test conditions employed (around 0.1 mg g{sup -1}) but these improve upon steam activation (around 0.25 mg g{sup -1}) but are still lower than those of non-impregnated commercial activated carbons (around 0.4-0.7 mg g{sup -1}), due to their lower surface areas. Comparable improvements to the commercial carbons have been achieved for impregnation treatments, including sulfur and bromine. However, certain gasification chars do have much higher breakthrough capacities than commercial carbons used for flue gas injection. Manganese oxide impregnation with low concentration is particularly effective for the activated and unactivated carbons giving breakthrough capacities comparable to the commercial carbons. Pointers for further increasing breakthrough and equilibrium capacities for carbon-based sorbents are discussed. 7 refs., 1 fig., 3 tabs.

Activated carbon-supported CuO nanoparticles: a hybrid material for carbon dioxide adsorption

Science.gov (United States)

Boruban, Cansu; Esenturk, Emren Nalbant

2018-03-01

Activated carbon-supported copper(II) oxide (CuO) nanoparticles were synthesized by simple impregnation method to improve carbon dioxide (CO2) adsorption capacity of the support. The structural and chemical properties of the hybrid material were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (https://www.google.com.tr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CCsQFjAC&url=http%3A%2F%2Fwww.intertek.com%2Fanalytical-laboratories%2Fxrd%2F&ei=-5WZVYSCHISz7Aatqq-IAw&usg=AFQjCNFBlk-9wqy49foh8tskmbD-GGbG9g&sig2=eKrhYjO75rl_Id2sLGpq4w&bvm=bv.96952980,d.bGg) (XRD), X-ray photoelectron spectroscopy (XPS), atomic absorption spectroscopy (AAS), and Brunauer-Emmett-Teller (BET) analyses. The analyses showed that CuO nanoparticles are well-distributed on the activated carbon surface. The CO2 adsorption behavior of the activated carbon-supported CuO nanoparticles was observed by thermogravimetric analysis (TGA), temperature programmed desorption (TPD), Fourier transform infrared (FTIR), and BET analyses. The results showed that CuO nanoparticle loading on activated carbon led to about 70% increase in CO2 adsorption capacity of activated carbon under standard conditions (1 atm and 298 K). The main contributor to the observed increase is an improvement in chemical adsorption of CO2 due to the presence of CuO nanoparticles on activated carbon.

Swelling kinetics and impregnation of PLA with thymol under supercritical CO2 conditions

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Milovanović Stoja L.

2016-01-01

Full Text Available The present work was aimed to study swelling kinetics of polylactic acid (PLA and its impregnation with thymol in supercritical carbon dioxide (scCO2 medium. The influences of temperature and soaking time on the swelling kinetics and impregnation yield of PLA cylindrical disc and film were investigated. Swelling experiments were performed in a high pressure view cell at 10 MPa and temperatures of 40°C, 60°C and 75°C for 2 to 24 h. On the basis of swelling kinetics, pressure of 10 MPa and temperature of 40°C were chosen for supercritical solvent impregnation (SSI of the PLA samples during 2 to24 h. The highest swelling extent was observed for the PLA monolith after 24 h treatment with pure scCO2 (7.5% and scCO2 with thymol (118.3%. It was shown that sufficiently high amount of thymol can be loaded into both PLA monolith and film using SSI after only 2 h (10.0% and 6.6%, respectively. Monolith and film of PLA impregnated with thymol could be suitable for active food packaging and sterile medical disposables.

Activated Carbon from the Chinese Herbal Medicine Waste by H3PO4 Activation

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Tie Mi

2015-01-01

Full Text Available Large amounts of Chinese herbal medicine wastes produced by the medicinal factories have been mainly landfilled as waste. In this study, via phosphoric acid activation, a Chinese herbal medicine waste from Magnolia officinalis (CHMW-MO was prepared for activated carbon (CHMW-MO-AC. The effect of preparation conditions (phosphoric acid/CHMW-MO impregnation ratio, activation temperature, and time of activated carbon on yield of CHMW-MO-AC was investigated. The surface area and porous texture of the CHMW-MO-ACs were characterized by nitrogen adsorption at 77 K. The SBET and pore volume were achieved in their highest value of 920 m2/g and 0.703 cm3/g, respectively. Thermal gravity analysis and scanning electron microscope images showed that CHMW-MO-ACs have a high thermal resistance and pore development. The results indicated that CHMW-MO is a good precursor material for preparing activated carbon, and CHMW-MO-AC with well-developed mesopore volume can be prepared by H3PO4 activation.

Effects of Activated Carbon Surface Property on Structure and Activity of Ru/AC Catalysts

Science.gov (United States)

Xu, S. K.; Li, L. M.; Guo, N. N.

2018-05-01

The activated carbon (AC) was modified by supercritical (SC) methanol, HNO3 oxidation, or HNO3 oxidation plus SC methanol, respectively. Then, the original and the modified AC were used as supports for Ru/AC catalysts prepared via the impregnation method. The results showed that the SC methanol modification decreased the content of surface acidic groups of AC. While HNO3 oxidation displayed the opposite behavior. Furthermore, the dispersion of ruthenium and the activity of catalysts were highly dependent on the content of surface acidic groups, and the SC methanol modified sample exhibited the highest activity for hydrogenation of glucose.

Adsorption Isotherm of Chromium (Vi) into Zncl2 Impregnated Activated Carbon Derived by Jatropha Curcas Seed Hull

Science.gov (United States)

Mohammad, M.; Yakub, I.; Yaakob, Z.; Asim, N.; Sopian, K.

2017-12-01

Hexavalent chromium is carcinogenic and should be removed from industrial wastewater before discharged into water resources. Adsorption by using activated carbon from biomass is an economic and conventional way on removing the heavy metal ions from wastewater. In this research, activated carbon is synthesized from Jatropha curcas L. seed hull through chemical activation with ZnCl2 and carbonized at 800 °C (JAC/ZnCl2). The activated carbon has been characterized using FTIR, SEM-EDX, BET and CHNS-O analyzer. Adsorption isotherms have been analysed using Langmuir and Freundlich models to determine its removal mechanism. The maximum adsorption capacity of Cr (VI) metal ions onto JAC/ZnCl2 activated carbon is 25.189 mg/g and following Langmuir isotherm model which is monolayer adsorption.

Preparation and Characterization of Activated Carbon Fibers from Liquefied Wood by ZnCl2 Activation

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Zhigao Liu

2016-02-01

Full Text Available In this study, activated carbon fibers (ACFs were prepared from liquefied wood by chemical activation with ZnCl2, with a particular focus on the effects of temperature and ZnCl2: liquefied wood-based fiber (LWF ratio on yield, porous texture, and surface chemistry. The characterization and properties of these ACFs were investigated by nitrogen adsorption/desorption, Fourier transform infrared (FTIR spectroscopy, and X-ray photoelectron spectroscopy (XPS. When using a 6:1 impregnation ratio, the specific surface area (SBET of the resultant ACFs was as high as 1423 m2/g. The effect of an increase in impregnation ratio on the porosity of ACFs was stronger than that of an increase in the activation temperature. However, the former had a weaker impact on the surface chemistry and structure. It was also found that the yields of ACFs obtained by ZnCl2 activation were higher than those obtained by physical activation. Besides, the prepared ACFs presented higher adsorption than other raw materials in the adsorption test, indicating that ACFs prepared from LWF by ZnCl2 activation could be used as an adsorbent for the adsorption of medium size organic compounds.

Estimates of increased black carbon emissions from electrostatic precipitators during powdered activated carbon injection for mercury emissions control.

Science.gov (United States)

Clack, Herek L

2012-07-03

The behavior of mercury sorbents within electrostatic precipitators (ESPs) is not well-understood, despite a decade or more of full-scale testing. Recent laboratory results suggest that powdered activated carbon exhibits somewhat different collection behavior than fly ash in an ESP and particulate filters located at the outlet of ESPs have shown evidence of powdered activated carbon penetration during full-scale tests of sorbent injection for mercury emissions control. The present analysis considers a range of assumed differential ESP collection efficiencies for powdered activated carbon as compared to fly ash. Estimated emission rates of submicrometer powdered activated carbon are compared to estimated emission rates of particulate carbon on submicrometer fly ash, each corresponding to its respective collection efficiency. To the extent that any emitted powdered activated carbon exhibits size and optical characteristics similar to black carbon, such emissions could effectively constitute an increase in black carbon emissions from coal-based stationary power generation. The results reveal that even for the low injection rates associated with chemically impregnated carbons, submicrometer particulate carbon emissions can easily double if the submicrometer fraction of the native fly ash has a low carbon content. Increasing sorbent injection rates, larger collection efficiency differentials as compared to fly ash, and decreasing sorbent particle size all lead to increases in the estimated submicrometer particulate carbon emissions.

Effect of Activation Temperature and Heating Duration on Physical Characteristics of Activated Carbon Prepared from Agriculture Waste

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Tham Yee Jun

2010-01-01

Full Text Available This study was conducted to determine the physical characteristics of activated carbon prepared from durian shell in varied heating durations from 10 min to 30 min and activation temperatures of 400C and 500C. Durian shells have been characterized in term of ultimate and proximate analysis, chemical composition and thermal behaviour with a view to be used as activated carbon precursor. Durian shell activated carbon was prepared by impregnating 10g of sample in 10% (v/v concentration of phosphoric acid for 24 h, followed by carbonization at 400C and 500C with different heating durations under nitrogen atmosphere. The results showed that various treatment conditions affect the percentage of yield, BET surface area, micropore volume, and average pore diameter. The highest surface area (SBET 1024 m2/g was obtained at 500C and 20 min of heating duration with 63% of yield and 0.21 cm3/g micropore volume.

Evaluation of the SO(2) and NH(3) gas adsorption properties of CuO/ZnO/Mn(3)O(4) and CuO/ZnO/NiO ternary impregnated activated carbon using combinatorial materials science methods.

Science.gov (United States)

Romero, Jennifer V; Smith, Jock W H; Sullivan, Braden M; Macdonald, Landan; Croll, Lisa M; Dahn, J R

2013-02-11

Impregnated activated carbons (IAC) are widely used materials for the removal of toxic gases in personal respiratory protection applications. The combinatorial method has been employed to prepare IACs containing different types of metal oxides in various proportions and evaluate their adsorption performance for low molecular weight gases, such as SO(2) and NH(3), under dry conditions. Among the metal oxides used for the study, Mn(3)O(4) was found to have the highest capacity for retaining SO(2) gas under dry conditions. NiO and ZnO were found to have similar NH(3) adsorption capacities which are higher than the NH(3) capacities observed for the other metal oxide impregnants used in the study. Although Cu- or Zn-based impregnants and their combinations have been extensively studied and used as gas adsorbents, neither Mn(3)O(4) nor NiO have been incorporated in the formulations used. In this study, ternary libraries of IACs with various combinations of CuO/ZnO/Mn(3)O(4) and CuO/ZnO/NiO were studied and evaluated for their adsorption of SO(2) and NH(3) gases. Combinations of CuO, ZnO, and Mn(3)O(4) were found to have the potential to be multigas adsorbents compared to formulations that contain NiO.

Effects Of Aging And Oxidation Of Palladized Iron Embedded In Activated Carbon On The Dechlorination Of 2-Chlorobiphenyl

Science.gov (United States)

Reactive activated carbon (RAC) impregnated with palladized iron has been developed to effectively treat polychlorinated biphenyls (PCBs) in the environment by coupling adsorption and dechlorination of PCBs. In this study, we addressed the dechlorination reactivity and capacity ...

Adsorption/oxidation of sulfur-containing gases on nitrogen-doped activated carbon

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Liu Qiang

2016-01-01

Full Text Available Coconut shell-based activated carbon (CAC was used for the removal of methyl mercaptan (MM. CAC was modified by urea impregnation and calcined at 450°C and 950°C. The desulfurization activity was determined in a fixed bed reactor under room temperature. The results showed that the methyl mercaptan adsorption/oxidation capacity of modified carbon caicined at 950°C is more than 3 times the capacity of original samples. On the other hand, the modified carbon caicined at 950°C also has a high capacity for the simultaneous adsorption/oxidation of methyl mercaptan and hydrogen sulfide.The introduce of basic nitrogen groups siginificantly increases the desulfurization since it can facilitate the electron transfer process between sulfur and oxygen. The structure and chemical properties are characterized using Boehm titration, N2 adsorption-desorption method, thermal analysis and elemental analysis. The results showed that the major oxidation products were dimethyl disulfide and methanesulfonic acid which adsorbed in the activated carbon.

Development of activated charcoal impregnated air sampling filter media : their characteristics and use

International Nuclear Information System (INIS)

Khan, A.A.; Ramarathinam, K.; Gupta, S.K.; Deshingkar, D.S.; Kishore, A.G.

1975-01-01

Because of its low maximum permissible concentration in air, air-borne radioiodine must be accurately monitored in contaminated air streams, in the working environment and handling facilities, before release to the environment from the nuclear facilities. Activated charcoal impregnated air sampling filter media are found to be most suitable for monitoring airborne iodine-131. Because of its simplicity and reproducible nature in assessment of air-borne radioactive iodine, the work on the development of such media was undertaken in order to find a suitable substitute for imported activated charcoal impregnated air sampling filter media. Eight different media of such type were developed, evaluated and compared with two imported media. Best suitable medium is recommended for its use in air-borne iodine sampling which was found to be even better suited than imported media of such type. (author)

Porous structure and surface chemistry of phosphoric acid activated carbon from corncob

Science.gov (United States)

Sych, N. V.; Trofymenko, S. I.; Poddubnaya, O. I.; Tsyba, M. M.; Sapsay, V. I.; Klymchuk, D. O.; Puziy, A. M.

2012-11-01

Active carbons have been prepared from corncob using chemical activation with phosphoric acid at 400 °C using varied ratio of impregnation (RI). Porous structure of carbons was characterized by nitrogen adsorption and scanning electron microscopy. Surface chemistry was studied by IR and potentiometric titration method. It has been shown that porosity development was peaked at RI = 1.0 (SBET = 2081 m2/g, Vtot = 1.1 cm3/g), while maximum amount of acid surface groups was observed at RI = 1.25. Acid surface groups of phosphoric acid activated carbons from corncob includes phosphate and strongly acidic carboxylic (pK = 2.0-2.6), weakly acidic carboxylic (pK = 4.7-5.0), enol/lactone (pK = 6.7-7.4; 8.8-9.4) and phenol (pK = 10.1-10.7). Corncob derived carbons showed high adsorption capacity to copper, especially at low pH. Maximum adsorption of methylene blue and iodine was observed for carbon with most developed porosity (RI = 1.0).

Preparation and characterization of activated carbon from castor de-oiled cake

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Viviana M. Ospina-Guarín

2014-01-01

Full Text Available Biomass residues have been used to produce activated carbons. On this process, the activation method and the raw composition determine the properties as porosity and surface area of the charcoal. After the extraction of castor oil, there is a solid byproduct (cake of low added value, which was used in the production of activated carbon to add value to this waste. For this purpose two traditional methods were used, first, physical activation using as activating agents steam, CO2 and mixture of both, and additionally chemical activation using K2CO3 as the activating agent. Some activated carbons were characterized using N2 adsorption isotherms, BET surface areas varied between 255.98 (m2/g and 1218.43 (m2/g. By SEM and EDS analysis was possible to observe that materials obtained by the two types of activation are principally amorphous and morphological characteristics of the carbon obtained by physical activation are very different from those obtained by chemical activation. Finally, through impregnation of inorganic phases of Ni and Mo was revealed that the high dispersion characteristics, these carbonaceous materials will have potential to be used as catalyst support.

Nanoscale zero-valent iron impregnation of covalent organic polymer grafted activated carbon for water treatment

DEFF Research Database (Denmark)

Mines, Paul D.; Uthuppu, Basil; Thirion, Damien

2016-01-01

The use of nanoscale zero valent iron (nZVI) has quickly become a leading research material for the treatment of typically hard to degrade contaminants found in groundwater. These contaminants include antibiotics, pesticides, halogenated organics, heavy metals, among others. However, the effectiv......The use of nanoscale zero valent iron (nZVI) has quickly become a leading research material for the treatment of typically hard to degrade contaminants found in groundwater. These contaminants include antibiotics, pesticides, halogenated organics, heavy metals, among others. However...... polymeric network already previously proven to stabilize nZVI and a long-standing water treatment material,1 activated carbon; we have developed an advanced material that allows for the not only the stabilization of nZVI, but also the improved degradation of various water contaminants. This was done...... by performing a series of surface modification techniques to the surface of the activated carbon, then physically grafting the covalent organic polymer to the carbon in a shell-like manner, and ultimately synthesizing nZVI in situ within the pores of both the activated carbon and the polymeric network. Not only...

Background electrolytes and pH effects on selenate adsorption using iron-impregnated granular activated carbon and surface binding mechanisms.

Science.gov (United States)

Zhang, Ning; Gang, Daniel Dianchen; McDonald, Louis; Lin, Lian-Shin

2018-03-01

Iron-impregnated granular activated carbon (Fe-GAC) has been shown effective for selenite adsorptive removal from aqueous solutions, but similar effectiveness was not observed with selenate. This study examined the effects of background electrolytes and pH on selenate adsorption on to Fe-GAC, and surface bindings to elucidate the selenate adsorption mechanisms. The decrease magnitude of selenate adsorption capacity under three background electrolytes followed the order: LiCl > NaCl > KCl, as ionic strength increased from 0.01 to 0.1 M. Larger adsorption capacity differences among the three electrolytes were observed under the higher ionic strengths (0.05 and 0.1 M) than those under 0.01 M. Multiplet peak fittings of high resolution X-ray photoelectron spectra for O1s and Fe2p 3/2 indicated the presence of iron (III) on adsorbent surface. pH variations during the adsorbent preparation within 3-8 in NaCl solutions did not cause appreciable changes in the iron redox state and composition. Raman spectra showed the formation of both monodentate and bidentate inner sphere complexes under pHs adsorption under alkaline conditions. Mechanisms for monodentate and bidentate formations and a stable six-member ring structure were proposed. Two strategies were recommended for modifying Fe-GAC preparation procedure to enhance the selenate adsorption: (1) mixed-metal oxide coatings to increase the point of zero charge (pH zpc ); and (2) ferrous iron coating to initially reduce selenate followed by selenite adsorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adsorptive removal of phenol from aqueous solutions on activated carbon prepared from tobacco residues: Equilibrium, kinetics and thermodynamics

Energy Technology Data Exchange (ETDEWEB)

Kilic, Murat; Apaydin-Varol, Esin [Department of Chemical Engineering, Anadolu University, Eskisehir 26470 (Turkey); Puetuen, Ayse E., E-mail: aeputun@anadolu.edu.tr [Department of Chemical Engineering, Anadolu University, Eskisehir 26470 (Turkey)

2011-05-15

This study consists of producing high surface area activated carbon from tobacco residues by chemical activation and its behavior of phenol removal from aqueous solutions. K{sub 2}CO{sub 3} and KOH were used as chemical activation agents and three impregnation ratios (50, 75 and 100 wt.%) were applied on biomass. Maximum BET surface areas of activated carbons were obtained from impregnation with 75 wt.% of K{sub 2}CO{sub 3} and 75 wt.% of KOH as 1635 and 1474 m{sup 2}/g, respectively. Optimum adsorption conditions were determined as a function of pH, adsorbent dosage, initial phenol concentration, contact time and temperature of solution for phenol removal. To describe the equilibrium isotherms the experimental data were analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherm models. Pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models were used to find out the kinetic parameters and mechanism of adsorption process. The thermodynamic parameters such as {Delta}G{sup o}, {Delta}H{sup o} and {Delta}S{sup o} were calculated for predicting the nature of adsorption. According to the experimental results, activated carbon prepared from tobacco residue seems to be an effective, low-cost and alternative adsorbent precursor for the removal of phenol from aqueous solutions.

Esterification of fatty acids using sulfated zirconia and composites activated carbon/sulfated zirconia catalysts

International Nuclear Information System (INIS)

Brum, Sarah S.; Santos, Valeria C. dos; Destro, Priscila; Guerreiro, Mario Cesar

2011-01-01

In this work sulfated zirconia (SZr) and activated carbon/SZr composites produced by impregnation method with or without heating treatment step (CABC/SZr-I and CABC/SZr-I SC) and by the method of synthesis of SZr on the carbon (CABC/SZr-S) was used as catalysts in the esterification reactions of fatty acids. The SZr presented very active, conversions higher than 90% were obtained after 2 h of reaction. The activity of the composite CABC/SZr-I20%SC was up to 92%, however, this was directly related to time and temperature reactions. CABC/SZr-I and CABC/SZr-S were less active in esterification reactions, what could be attributed to its low acidity. (author)

Adsorption of mercury (II from liquid solutions using modified activated carbons

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Hugo Soé Silva

2010-06-01

Full Text Available Mercury is one of the most toxic metals present in the environment. Adsorption has been proposed among the technologies for mercury abatement. Activated carbons are universal adsorbents which have been found to be a very effective alternative for mercury removal from water. The effectiveness with which a contaminant is adsorbed by the solid surface depends, among other factors, on the charge of the chemical species in which the contaminant is in solution and on the net charge of the adsorbent surface which depend on the pH of the adsorption system. In this work, activated carbon from carbonized eucalyptus wood was used as adsorbent. Two sulphurization treatments by impregnation with sulphuric acid and with carbon disulphide, have been carried out to improve the adsorption capacity for mercury entrapment. Batch adsorption tests at different temperatures and pH of the solution were carried out. The influence of the textural properties, surface chemistry and operation conditions on the adsorption capacity, is discussed.

Multi-electrode double layer capacitor having single electrolyte seal and aluminum-impregnated carbon cloth electrodes

Science.gov (United States)

Farahmandi, C. Joseph; Dispennette, John M.; Blank, Edward; Kolb, Alan C.

1999-01-19

A single cell, multi-electrode high performance double layer capacitor includes first and second flat stacks of electrodes adapted to be housed in a closeable two-part capacitor case which includes only a single electrolyte seal. Each electrode stack has a plurality of electrodes connected in parallel, with the electrodes of one stack being interleaved with the electrodes of the other stack to form an interleaved stack, and with the electrodes of each stack being electrically connected to respective capacitor terminals. A porous separator sleeve is inserted over the electrodes of one stack before interleaving to prevent electrical shorts between the electrodes. The electrodes are made by folding a compressible, low resistance, aluminum-impregnated carbon cloth, made from activated carbon fibers, around a current collector foil, with a tab of the foils of each electrode of each stack being connected in parallel and connected to the respective capacitor terminal. The height of the interleaved stack is somewhat greater than the inside height of the closed capacitor case, thereby requiring compression of the interleaved electrode stack when placed inside of the case, and thereby maintaining the interleaved electrode stack under modest constant pressure. The closed capacitor case is filled with an electrolytic solution and sealed. A preferred electrolytic solution is made by dissolving an appropriate salt into acetonitrile (CH.sub.3 CN). In one embodiment, the two parts of the capacitor case are conductive and function as the capacitor terminals.

Spent coffee grounds-based activated carbon preparation for sequestering of malachite green

Science.gov (United States)

Lim, Jun-Wei; Lam, Keat-Ying; Bashir, Mohammed J. K.; Yeong, Yin-Fong; Lam, Man-Kee; Ho, Yeek-Chia

2016-11-01

The key of reported work was to optimize the fabricating factors of spent coffee grounds-based activated carbon (SCG-bAC) used to sequester Malachite Green (MG) form aqueous solution via adsorption process. The fabricating factors of impregnation ratio with ortho-phosphoric acid, activation temperature and activation time were simultaneously optimized by central composite design (CCD) of response surface methodology (RSM) targeting on maximum removal of MG. At the optimum condition, 96.3% of MG was successfully removed by SCG-bAC at the impregnation ratio with ortho-phosphoric acid of 0.50, activation temperature of 554°C and activation time of 31.4 min. Statistical model that could predict the MG removal percentage was also derived and had been statistically confirmed to be significant. Subsequently, the MG adsorption equilibrium data was found well-fitted to Langmuir isotherm model, indicating the predominance of monolayer adsorption of MG on SCG-bAC surface. To conclude, the findings from the this study unveil the potential of spent coffee grounds as an alternative precursor in fabricating low-cost AC for the treatment of wastewater loaded with MG pollutant.

Effect of commercial activated carbons in sulfur cathodes on the electrochemical properties of lithium/sulfur batteries

Energy Technology Data Exchange (ETDEWEB)

Park, Jin-Woo; Kim, Icpyo [School of Materials Science and Engineering, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Kim, Ki-Won; Nam, Tae-Hyun; Cho, Kwon-Koo; Ahn, Jou-Hyeon [Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Ryu, Ho-Suk [Department of Material and Energy Engineering, Gyeongwoon University, 730, Gangdong-ro, Sandong-myeon, Gumi, Gyeongbuk, 39160 (Korea, Republic of); Ahn, Hyo-Jun, E-mail: ahj@gnu.ac.kr [School of Materials Science and Engineering, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of)

2016-10-15

Highlights: • The sulfur/activated carbon composite is fabricated using commercial activated carbons. • The sulfur/activated carbon composite with coal shows the best performance. • The Li/S battery has capacities of 1240 mAh g{sup −1} at 1 C and 567 mAh g{sup −1} at 10 C. - Abstract: We prepared sulfur/active carbon composites via a simple solution-based process using the following commercial activated carbon-based materials: coal, coconut shells, and sawdust. Although elemental sulfur was not detected in any of the sulfur/activated carbon composites based on Thermogravimetric analysis, X-ray diffraction, and Raman spectroscopy, Energy-dispersive X-ray spectroscopy results confirmed its presence in the activated carbon. These results indicate that sulfur was successfully impregnated in the activated carbon and that all of the activated carbons acted as sulfur reservoirs. The sulfur/activated carbon composite cathode using coal exhibited the highest discharge capacity and best rate capability. The first discharge capacity at 1 C (1.672 A g{sup −1}) was 1240 mAh g{sup −1}, and a large reversible capacity of 567 mAh g{sup −1} was observed at 10 C (16.72 A g{sup −1}).

Nanostructured composite TiO{sub 2}/carbon catalysts of high activity for dehydration of n-butanol

Energy Technology Data Exchange (ETDEWEB)

Cyganiuk, Aleksandra [Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Torun (Poland); Klimkiewicz, Roman [Institute of Low Temperature and Structure Research PAN, 50-422 Wroclaw (Poland); Bumajdad, Ali [Faculty of Science, Kuwait University, PO Box 5969 Safat, Kuwait 13060 (Kuwait); Ilnicka, Anna [Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Torun (Poland); Lukaszewicz, Jerzy P., E-mail: jerzy_lukaszewicz@o2.pl [Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Torun (Poland)

2015-08-15

Highlights: • New biotechnological method for fabrication of composite catalysts. • In situ synthesis of nanosized TiO{sub 2} clusters in the carbon matrix. • High dispersion of TiO{sub 2} in carbon matrix. • High catalytic activity achieved for very low active phase content. • Efficient dehydration of n-butanol to butane-1. - Abstract: A novel method of wood impregnation with titanium ions is presented. Titanium(IV) ions were complexed to peroxo/hydroxo complexes which were obtained by treating a TiCl{sub 4} water solution with H{sub 2}O{sub 2}. The solution of chelated titanium ions was used for the impregnation of living stems of Salix viminalis wood. Saturated stems were carbonized at 600–800 °C, yielding a microporous carbon matrix, in which nanoparticles of TiO{sub 2} were uniformly distributed. A series of composite TiO{sub 2}–carbon catalysts was manufactured and tested in the process of n-butanol conversion to butane-1. The composite catalysts exhibited very high selectivity (ca. 80%) and yield (ca. 30%) despite a low content of titanium (ca. 0.5% atomic). The research proved that the proposed functionalization led to high dispersion of the catalytic phase (TiO{sub 2}), which played a crucial role in the catalyst performance. High dispersion of TiO{sub 2} was achieved due to a natural transport of complexed titanium ions in living plant stems.

Preparation of activated carbon fabrics from cotton fabric precursor

Science.gov (United States)

Salehi, R.; Dadashian, F.; Abedi, M.

2017-10-01

The preparation of activated carbon fabrics (ACFs) from cotton fabric was performed by chemical activation with phosphoric acid (H3PO4). The operation conditions for obtaining the ACFs with the highest the adsorption capacity and process yield, proposed. Optimized conditions were: impregnation ratio of 2, the rate of temperature rising of 7.5 °C min-1, the activation temperature of 500 °C and the activation time of 30 min. The ACFs produced under optimized conditions was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The surface area and pore volume of carbon nanostructures was characterized by BET nitrogen adsorption isotherm at 77 °K. The pore size distribution calculated from the desorption branch according to BJH method. The iodine number of the prepared ACFs was determined by titration at 30 °C based on the ASTM D4607-94. The results showed the improvement of porous structure, fabric shape, surface area (690 m2/g), total pore volume (0.3216 cm3/g), and well-preserved fibers integrity.

Hydrogen production using thermocatalytic decomposition of methane on Ni30/activated carbon and Ni30/carbon black.

Science.gov (United States)

Srilatha, K; Viditha, V; Srinivasulu, D; Ramakrishna, S U B; Himabindu, V

2016-05-01

Hydrogen is an energy carrier of the future need. It could be produced from different sources and used for power generation or as a transport fuel which mainly in association with fuel cells. The primary challenge for hydrogen production is reducing the cost of production technologies to make the resulting hydrogen cost competitive with conventional fuels. Thermocatalytic decomposition (TCD) of methane is one of the most advantageous processes, which will meet the future demand, hence an attractive route for COx free environment. The present study deals with the production of hydrogen with 30 wt% of Ni impregnated in commercially available activated carbon and carbon black catalysts (samples coded as Ni30/AC and Ni30/CB, respectively). These combined catalysts were not attempted by previous studies. Pure form of hydrogen is produced at 850 °C and volume hourly space velocity (VHSV) of 1.62 L/h g on the activity of both the catalysts. The analysis (X-ray diffraction (XRD)) of the catalysts reveals moderately crystalline peaks of Ni, which might be responsible for the increase in catalytic life along with formation of carbon fibers. The activity of carbon black is sustainable for a longer time compared to that of activated carbon which has been confirmed by life time studies (850 °C and 54 sccm of methane).

Evaluation of sampling methods for measuring exposure to volatile inorganic acids in workplace air. Part 2: Sampling capacity and breakthrough tests for sodium carbonate-impregnated filters.

Science.gov (United States)

Demange, Martine; Oury, Véronique; Rousset, Davy

2011-11-01

In France, the MétroPol 009 method used to measure workplace exposure to inorganic acids, such as HF, HCl, and HNO3, consists of a closed-face cassette fitted with a prefilter to collect particles, and two sodium carbonate-impregnated filters to collect acid vapor. This method was compared with other European methods during the development of a three-part standard (ISO 21438) on the determination of inorganic acids in workplace air by ion chromatography. Results of this work, presented in a companion paper, led to a need to go deeper into the performance of the MétroPol 009 method regarding evaluation of the breakthrough of the acids, both alone and in mixtures, interference from particulate salts, the amount of sodium carbonate required to impregnate the sampling filter, the influence of sampler components, and so on. Results enabled improvements to be made to the sampling device with respect to the required amount of sodium carbonate to sample high HCl or HNO3 concentrations (500 μL of 5% Na2CO3 on each of two impregnated filters). In addition, a PVC-A filter used as a prefilter in a sampling device showed a propensity to retain HNO3 vapor so a PTFE filter was considered more suitable for use as a prefilter. Neither the material of the sampling cassette (polystyrene or polypropylene) nor the sampling flowrate (1 L/min or 2 L/min) influenced the performance of the sampling device, as a recovery of about 100% was achieved in all experiments for HNO3, HCl, and HF, as well as HNO3+HF and HNO3+HCl mixtures, over a wide range of concentrations. However, this work points to the possibility of interference between an acid and salts of other acids. For instance, interference can occur through interaction of HNO3 with chloride salts: the stronger the acid, the greater the interference. Methods based on impregnated filters are reliable for quantitative recovery of inorganic volatile acids in workplace atmosphere but are valuable only in the absence of interferents.

Adsorption of basic Red 46 using sea mango (Cerbera odollam) based activated carbon

Science.gov (United States)

Azmi, Nur Azira Iqlima; Zainudin, Nor Fauziah; Ali, Umi Fazara Md

2015-05-01

Sea mango or Cerbera Odollam is another source of carbonaceous material that can be found abundantly in Malaysia. In this research, it is used as a new agricultural source of activated carbon. Sea mango activated carbon was prepared by chemical activation using potassium hydroxide (KOH). The sea mango was soaked in KOH at impregnation ratio of 1:1 and followed by carbonization at temperature of 600°C for 1 hour. The sample was then characterized using Scanning Electron Microscope (SEM) for surface morphology, while Brunauer-Emmett-Teller (BET) was used to study the surface area. The result shown that sea mango activated carbon (SMAC) developed new pores on its surface and the BET surface area measured was 451.87 m2/g. The SMAC performance was then tested for the removal of Basic Red 46 in batch process. The removal of Basic Red 46 (50 mg/L, natural pH, 0.1 g SMAC) was more than 99% in 15 minutes where it reached equilibrium in 30 minutes.

Adsorption of basic Red 46 using sea mango (Cerbera odollam) based activated carbon

Energy Technology Data Exchange (ETDEWEB)

Azmi, Nur Azira Iqlima; Zainudin, Nor Fauziah [School of Bioprocess Engineering, Universiti Malaysia Perlis, Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis (Malaysia); Ali, Umi Fazara Md [School of Environmental Engineering, Universiti Malaysia Perlis, Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis (Malaysia)

2015-05-15

Sea mango or Cerbera Odollam is another source of carbonaceous material that can be found abundantly in Malaysia. In this research, it is used as a new agricultural source of activated carbon. Sea mango activated carbon was prepared by chemical activation using potassium hydroxide (KOH). The sea mango was soaked in KOH at impregnation ratio of 1:1 and followed by carbonization at temperature of 600°C for 1 hour. The sample was then characterized using Scanning Electron Microscope (SEM) for surface morphology, while Brunauer-Emmett-Teller (BET) was used to study the surface area. The result shown that sea mango activated carbon (SMAC) developed new pores on its surface and the BET surface area measured was 451.87 m{sup 2}/g. The SMAC performance was then tested for the removal of Basic Red 46 in batch process. The removal of Basic Red 46 (50 mg/L, natural pH, 0.1 g SMAC) was more than 99% in 15 minutes where it reached equilibrium in 30 minutes.

Functionalized polymer-based spherical activated carbon for liquid and gas phase applications

International Nuclear Information System (INIS)

Schrage, Christian; Modrow, Antje; Fichtner, Sven; Giebelhausen, Jann Michael; Boehringer, Bertram

2014-01-01

Polymer-based spherical activated carbon (PBSAC) can be functionalized through the integration of reactive compounds. This offers new fields of applications for this adsorbent material. Impregnated PBSAC can be used as broadband sorbent material for respiratory protection, and for removal of certain metals from water, while the integration of nitrogen leads to a material suitable for the clean-up of gases. Functionalization through oxidation or integration of nitrogen atoms enables the concentration of valuable resources like uranium or gold.

Effectiveness of Nigerian Bamboo Activated with Different Activating ...

African Journals Online (AJOL)

The effectiveness of Nigerian Bamboo activated with different activating agents on the adsorption of BTX was investigated. A series of activated carbons was prepared from Nigerian bamboo, carbonized at 400oC – 500oC and impregnated with different concentrations of four acids at 800oC in a muffle furnace for 2 hours.

Influence of surface properties on the mechanism of H2S removal by alkaline activated carbons.

Science.gov (United States)

Yan, Rong; Chin, Terence; Ng, Yuen Ling; Duan, Huiqi; Liang, David Tee; Tay, Joo Hwa

2004-01-01

sulfuric acid as the predominant products. Although both carbons are coal-based and of KOH impregnated type, performances of different carbons differ significantly. A correlation is well established to link the reaction extent with various surface properties. In summary, not only the homogeneous alkali impregnation and physical porosity but also the carbon surface chemistry are significant factors influencing the performances of alkaline activated carbons as H2S adsorbents.

Heterogeneous Catalysts for VOC Oxidation from Red Mud and Bagasse Ash Carbon

Science.gov (United States)

Pande, Gaurav

solids. The highest surface area of 311 m2/g was for the sample prepared from oxalic acid and l-ascorbic acid as the leaching acid; as received red mud has a surface area of 11.5 m2/g. This sample showed better catalytic performance than the ones made from hydrochloric acid as the leaching acid in spite of a similar increase in surface area. High temperature XRD shows the reason for this difference in catalytic properties could be due to both the solids reducing in a different way to give different phases though they are both derived from red mud as the starting material. Also, the sample prepared with oxalic acid leachate had higher surface iron concentration. For the best catalyst (oxalic acid derived) the light off temperature is about 300 °C for toluene oxidation. For solids prepared from red mud leachate for iron source and pickling acid for copper source, it was seen that the TPR gave hydrogen absorption at temperatures even lower than that for red mud leachate precipitates. In another set of experiments, iron oxide impregnated on activated carbon supports were prepared. Activated carbon is known for its adsorption properties which could give a better access of the impregnated metal oxide catalyst to perform the catalytic oxidation on the adsorbed substrate. Unburned carbon in bagasse ash which is a sugar industry agricultural waste was used to get the activated carbon. This material was separated from the ash and further modified to enhance the activity and increase the porosity. To this effect steam activation was performed. To impart thermal stability for oxidation reaction, the carbon was impregnated by phosphoric acid at activated at high temperatures in inert atmosphere. These carbons were thermally stable due to the surface C--O--P groups. Toluene adsorption studies were also performed for both the steam activated as well as phosphoric acid activated carbon and it was found that the steam activated carbons with less surface oxygen had reasonable adsorption

Temperature-programmed reduction and cyclic voltammetry of Pt/carbon-fibre paper catalysts for methanol electrooxidation

International Nuclear Information System (INIS)

Attwood, P.A.; McNicol, B.D.; Short, R.T.

1981-01-01

Temperature-programmed reduction (TPR) and cyclic voltammetry (CV) studies of platinum catalysts supported on pyrographite-coated carbon-fibre paper, and prepared by either ion exchange or impregnation, clearly demonstrate the nature of the interactions between the platinum species and the support. After drying the above catalysts at 120 0 C, the ion-exchanged preparation exhibits the stronger interaction with the carbon support, as might be expected since a chemical interaction with carbon surface groups is known to occur in such catalysts. The presence of a fraction of bulk Pt(NH 3 ) 4 (OH) 2 impregnating salt in the impregnated catalyst has been detected using TPR. After air activation at 300 0 C, subambient reduction peaks were observed and the strength of binding of Pt in the ion-exchanged catalyst was reflected by its increased difficulty of reduction in comparison with that of the impregnated catalyst. The stoichiometry of reduction in ion-exchanged catalysts corresponds to Pt 2+ → Pt 0 in both dried and activated catalysts, with a small amount of Pt 4+ present in the latter. Upon activation the impregnated catalyst showed the presence of some Pt metal, which was thought to arise from the decomposition of the fraction of bulk Pt(NH 3 ) 4 (OH) 2 in the dried catalyst. Activation of ion-exchanged catalysts at temperatures higher than 300 0 C led to a progressive weakening of the Pt-support interaction and consequent smaller Pt surface areas. Activation at 500 0 C in air produced Pt metal exclusively and very low Pt surface areas. The strong interaction between Pt and the carbon support upon activation of the ion-exchanged catalyst at 300 0 C is thought to be the origin of the large metal surface area and the high catalytic activity for methanol electrooxidation found upon reduction

Optimization of microwave-assisted durian seed based activated carbon preparation conditions for methylene blue dye removal

Science.gov (United States)

Ahmad, Mohd Azmier; Hamid, Siti Ruqayyah Ab.; Yusop, Mohamad Firdaus Mohamad; Aziz, Hamidi Abdul

2017-10-01

Due to easy access and relatively high fixed carbon content of 26.13% in its raw form, durian seed based activated carbon (DSAC) was produced via microwave heating. For activation stage, physiochemical approach consist of carbon dioxide (CO2) gasification and potassium hydroxide (KOH) as chemical activator were employed. Three most influential preparation variables on adsorption performance and yield of activated carbon (AC), which is radiation power, radiation time and KOH impregnation ratio (IR) were optimized with the help of response surface methodology (RSM). The optimization result revealed that 440W, 4.0 minutes and 0.55 of radiation power, radiation time and IR respectively, were needed to remove 80.23% of methylene blue (MB) dye and to obtain 25.77% of DSAC's yield. High Brunauer-Emmet-Teller (BET) surface area, total pore volume and average pore size of 852.30m2/g, 0.465cm3/g and 3.74nm respectively, were obtained on optimized DSAC.

Sulfur impregnated in tunable porous N-doped carbon as sulfur cathode: effect of pore size distribution

International Nuclear Information System (INIS)

Wang, Sha; Zhao, Zhenxia; Xu, Hui; Deng, Yuanfu; Li, Zhong; Chen, Guohua

2015-01-01

Highlights: •Effects of pore size were investigated on electrochemistry for S cathode. •Activation energy of sulfur desorption from the PDA-C was estimated. •Strong interaction was formed between sulfur and porous N-doped carbon. •PDA-C@S showed good cycling performance of 608 mA h g −1 at 2 C over 300 cycles. •PDA-C@S showed good rate stability and high rate capacity. -- Abstract: A novel porous N-doped carbon microsphere (polymer-dopamine derived carbon, PDA-C) with high specific surface area was synthesized as sulfur host for high performance of lithium-sulfur batteries. We used KOH to adjust the pore size and surface area of the PDA-C materials, and then impregnated sulfur into the PDA-C samples by vapor-melting diffusion method. Effects of pore size of the PDA-C samples on the electrochemical performance of the PDA-C@sulfur cathodes were systematically investigated. Raman spectra indicated an enhanced trend of the degree of graphitization of the PDA-C samples with increasing calcination temperature. The surface area of the PDA-C samples increases with amount of the KOH in the pore-creating process. The graphitized porous N-doped carbon provides the high electronic conductive network. Meanwhile, the PDA-C with high surface area and uniform micropores ensures a high interaction toward sulfur as well as the high dispersion of nanoscale sulfur layer on it. The microporous PDA-C@S cathode material exhibits the excellent high rate discharge capability (636 mA h g −1 at 2.0 C) and good low/high-rate cycling stability (893 mA h g −1 (0.5 C) and 608 mA h g −1 (2.0 C) over 100 and 300 cycles). Cyclic voltammogram curves and electrochemical impedance plots show that both the impedance and polarization of the cells increase with decreasing pore size

Effect of Phosphoric Acid Concentration on the Characteristics of Sugarcane Bagasse Activated Carbon

Science.gov (United States)

Adib, M. R. M.; Suraya, W. M. S. W.; Rafidah, H.; Amirza, A. R. M.; Attahirah, M. H. M. N.; Hani, M. S. N. Q.; Adnan, M. S.

2016-07-01

Impregnation method is one of the crucial steps involved in producing activated carbon using chemical activation process. Chemicals employed in this step is effective at decomposing the structure of material and forming micropores that helps in adsorption of contaminants. This paper explains thorough procedures that have been involved in producing sugarcane bagasse activated carbon (SBAC) by using 5%, 10%, 20%, 30% phosphoric acid (H3PO4) during the impregnation step. Concentration of H3PO4 used in the process of producing SBAC was optimized through several tests including bulk density, ash content, iodine adsorption and pore size diameter and the charactesristic of optimum SBAC produced has been compared with commercial activated carbon (CAC). Batch study has been carried out by using the SBAC produced from optimum condition to investigate the performance of SBAC in removal of turbidity and chemical oxygen demand (COD) from textile wastewater. From characteristic study, SBAC with 30% H3PO4 has shown the optimum value of bulk density, ash content, iodine adsorption and pore size diameter of 0.3023 g cm-3, 4.35%, 974.96 mg/g and 0.21-0.41 µm, respectively. These values are comparable to the characteristics of CAC. Experimental result from the batch study has been concluded that the SBAC has a promising potential in removing turbidity and COD of 75.5% and 66.3%, respectively which was a slightly lower than CAC which were able to remove 82.8% of turbidity and 70% of COD. As a conclusion, the SBAC is comparable with CAC in terms of their characteristics and the capability of removing contaminants from textile wastewater. Therefore, it has a commercial value to be used as an alternative of low-cost material in producing CAC.

Effect of alkali metal content of carbon on retention of iodine at high temperatures

International Nuclear Information System (INIS)

Evans, A.G.

1975-01-01

Activated carbon for filters in reactor confinement systems is intentionally impregnated with iodine salts to enhance the removal of radioiodine from air streams containing organic iodides. When a variety of commercial impregnated carbons were evaluated for iodine retention at elevated temperatures (4 hours at 180 0 C), wide variations in iodine penetration were observed. The alkali metal and iodine content of carbon samples was determined by neutron activation analysis, and a strong correlation was shown between the atom ratio of iodine to alkali metals in the carbons and the high-temperature retention performance. Carbons containing excess alkali (especially potassium) have iodine penetration values 10 to 100 times lower than carbons containing excess iodine. Both low I/K ratios and high pH values were shown essential to high efficiency iodine retention; therefore, conversion of elemental iodine to ionic iodine is the basic reaction mechanism. The natural high K + content and high pH coconut carbons make coconut the preferred natural base material for nuclear air cleaning applications. Studies show, however, that treatment of low potassium carbons with a mixture of KOH and I 2 may produce a product equal to or better than I 2 -impregnated coconut carbons at a lower cost. (U.S.)

Adsorption/oxidation of hydrogen sulfide on nitrogen-containing activated carbons

Energy Technology Data Exchange (ETDEWEB)

Adib, F.; Bagreev, A.; Bandosz, T.J.

2000-02-22

Wood-based activated carbon was modified by impregnation with urea and heat treatment at 450 and 950 C. The chemical and physical properties of materials were determined using acid/base titration, FTIR, thermal analysis, IGC, and sorption of nitrogen. The surface features were compared to those of a commercial urea-modified carbon. Then, the H{sub 2}S breakthrough capacity tests were carried out, and the sorption capacity was evaluated. The results showed that urea-modified sorbents have a capacity similar to that of the received material; however, the conversion of hydrogen sulfide to a water-soluble species is significantly higher. It happens due to a high dispersion of basic nitrogen compounds in the small pores of carbons, where oxidation of hydrogen sulfide ions to sulfur radicals followed by the creation of sulfur oxides and sulfuric acid occurs. It is proposed that the process proceeds gradually, from small pores to larger, and that the degree of microporosity is an important factor.

Effects of impregnation methods and drying conditions on quinoline hydrodenitrogenation over Ni-W based catalysts

Energy Technology Data Exchange (ETDEWEB)

Guo, Fang; Qiu, Zegang; Zhao, Liangfu; Xiang, Hongwei [Institute of Coal Chemistry, Chinese Academy of Sciences (China); Guo, Shaoqing [Taiyuan University of Science and Technology (China)

2014-04-15

The effects of impregnation methods (co-impregnation and sequential impregnation) and drying conditions (air and vacuum) on the structure and catalytic behavior of MCM-41 supported Ni-W catalysts were investigated. The catalysts were characterized by powder X-ray diffraction (XRD) analysis, Fourier-transform infrared spectroscopy (FT-IR), diffuse reflectance UV-Vis absorbance spectroscopy (DRS), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and pyridine adsorbed infrared spectroscopy (Py-IR) techniques. They were tested for hydrodenitrogenation (HDN) of quinoline at temperatures of 300-400 deg C. The HDN results showed that the catalysts prepared by co-impregnation were more active than the catalysts prepared by sequential impregnation and the catalysts prepared by drying under vacuum were more active than the catalysts dried in air. Characterization revealed that the co-impregnation method and drying under vacuum promoted the dispersion of W, the formation of the active phases, and the formation of acidic sites on the catalysts. (author)

Adsorption of Carbon Dioxide onto Tetraethylenepentamine Impregnated PMMA Sorbents with Different Pore Structure

Energy Technology Data Exchange (ETDEWEB)

Jo, Dong Hyun; Park, Cheonggi; Jung, Hyunchul; Kim, Sung Hyun [Korea University, Seoul (Korea, Republic of)

2015-02-15

Poly(methyl methacrylate) (PMMA) supports and amine additives were investigated to adsorb CO{sub 2}. PMMA supports were fabricated by using different ratio of pore forming agents (porogen) to control the BET specific surface area, pore volume and distribution. Toluene and xylene are used for porogens. Supported amine sorbents were prepared by wet impregnation of tetraethylenepentamine (TEPA) on PMMA supports. So we could identify the effect of the pore structure of supports and the quantity of impregnated TEPA on the adsorption capacity. The increased amount of toluene as pore foaming agent resulted in the decreased average pore diameter and the increased BET surface area. Polymer supports with huge different pore distribution could be fabricated by controlling the ratio of porogen. After impregnation, the support with micropore structure is supposed the pore blocking and filling effect so that it has low CO{sub 2} capacity and kinetics due to the difficulty of diffusing. Macropore structure indicates fast adsorption capacity and low influence of amine loading. In case of support with mesopore, it has high performance of adsorption capacity and kinetics. So high surface area and meso-/macro- pore structure is suitable for CO{sub 2} capture.

Application of activated carbon fiber to a filter used for airborne radioiodine sampling

International Nuclear Information System (INIS)

Kato, Shohei; Murata, Mikio; Yoshikazu, Yoshida

1988-01-01

An airborne radioiodine sampling filter is required to have low pressure drop, mechanical strength enough to a practical use and high collection efficiency under high relative humidity(RH). To develop a filter to meet the requirements, the influences of impregnation amount of triethylenediamin(TEDA) on the collection efficiencies for methyl iodide and the reaction rates were investigated for several kinds of activated carbon fiber varied in specific surface area, pore diameter, etc. Silver silica gel(Sut Chemi, AC6120), silver zeolite(CTI Nuc., AgX Type III), silver alumina(Hitachi Co.) and granular activated charcoal were also examined for comparison. A new type filter made of activated carbon fiber (ACF filter) was developed based on the above experimental results. The ACF filter was examined for the pressure drop by the filter and collection efficiency for methyl iodide being compared with other types of filters such as an activated charcoal cartridge (ACC) and an activated charcoal filter paper (ACP)

Synthesis and Electrochemical Evaluation of Carbon Supported Pt-Co Bimetallic Catalysts Prepared by Electroless Deposition and Modified Charge Enhanced Dry Impregnation

Directory of Open Access Journals (Sweden)

John Meynard M. Tengco

2016-06-01

Full Text Available Carbon-supported bimetallic Pt-Co cathode catalysts have been previously identified as higher activity alternatives to conventional Pt/C catalysts for fuel cells. In this work, a series of Pt-Co/C catalysts were synthesized using electroless deposition (ED of Pt on a Co/C catalyst prepared by modified charge enhanced dry impregnation. X-ray diffraction (XRD and scanning transmission electron microscopy (STEM characterization of the base catalyst showed highly dispersed particles. A basic ED bath containing PtCl62− as the Pt precursor, dimethylamine borane as reducing agent, and ethylenediamine as stabilizing agent successfully targeted deposition of Pt on Co particles. Simultaneous action of galvanic displacement and ED resulted in Pt-Co alloy formation observed in XRD and energy dispersive X-ray spectroscopy (XEDS mapping. In addition, fast deposition kinetics resulted in hollow shell Pt-Co alloy particles while particles with Pt-rich shell and Co-rich cores formed with controlled Pt deposition. Electrochemical evaluation of the Pt-Co/C catalysts showed lower active surface but much higher mass and surface activities for oxygen reduction reaction compared to a commercial Pt/C fuel cell catalyst.

Central composite design approach towards optimization of flamboyant pods derived steam activated carbon for its use as heterogeneous catalyst in transesterification of Hevea brasiliensis oil

International Nuclear Information System (INIS)

Dhawane, Sumit H.; Kumar, Tarkeshwar; Halder, Gopinath

2015-01-01

Highlights: • Activated carbon was prepared from novel precursor flamboyant pods (Delonix regia). • Activation process was optimized using central composite design approach. • Prepared activated carbon at optimized condition was used as support for KOH. • Carbon based heterogeneous catalyst was used in transesterification of HBO. • Effect of catalyst loading and alcohol ratio on biodiesel yield was studied. - Abstract: The present investigation emphasises the preparation of carbon based KOH impregnated heterogeneous catalyst from flamboyant pods (Delonix regia) for the production of biodiesel from novel feedstock Hevea brasiliensis oil (HBO). Initially, carbonized char was physically activated by superheated steam and the process was optimized to study the effects of activation time and temperature by central composite design approach (CCD) using response surface methodology (RSM). Activated carbon was impregnated with KOH at four different ratios. Biodiesel production process was carried out at constant temperature 60 °C, reaction time 1 h, and 5 g of carbon based catalyst at varying quantities of catalyst loading (0.5, 2, 3.5, 5 wt%) and methanol to oil ratio (5:1–20:1). The influence of parameters on the biodiesel yield at varied condition was studied. Maximum yield of 89.3% was obtained at methanol to oil ratio 15:1 and catalyst loading 3.5 wt% and corresponding yield at same process parameters was observed to be 88.7% implying the significant activity of catalyst in reutilization. Produced biodiesel was characterized following ASTM standards. The experimental analysis confirmed that the carbonaceous catalyst developed from flamboyant pods under optimized condition is capable of transesterifying HBO into biodiesel

Factors Influencing NO2 Adsorption/Reduction on Microporous Activated Carbon: Porosity vs. Surface Chemistry

Directory of Open Access Journals (Sweden)

Imen Ghouma

2018-04-01

Full Text Available The textural properties and surface chemistry of different activated carbons, prepared by the chemical activation of olive stones, have been investigated in order to gain insight on the NO2 adsorption mechanism. The parent chemical activated carbon was prepared by the impregnation of olive stones in phosphoric acid followed by thermal carbonization. Then, the textural properties and surface chemistry were modified by chemical treatments including nitric acid, sodium hydroxide and/or a thermal treatment at 900 °C. The main properties of the parent and modified activated carbons were analyzed by N2-adsorption, scanning electron microscopy (SEM, and Fourier transform infrared spectroscopy (FTIR techniques, in order to enlighten the modifications issued from the chemical and thermal treatments. The NO2 adsorption capacities of the different activated carbons were measured in fixed bed experiments under 500 ppmv NO2 concentrations at room temperature. Temperature programmed desorption (TPD was applied after adsorption tests in order to quantify the amount of the physisorbed and chemisorbed NO2. The obtained results showed that the development of microporosity, the presence of oxygen-free sites, and the presence of basic surface groups are key factors for the efficient adsorption of NO2.

Preparation of a New Adsorbent from Activated Carbon and Carbon Nanofiber (AC/CNF for Manufacturing Organic-Vacbpour Respirator Cartridge

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Mehdi Jahangiri

2013-01-01

Full Text Available In this study a composite of activated carbon and carbon nanofiber (AC/CNF was prepared to improve the performance of activated carbon (AC for adsorption of volatile organic compounds (VOCs and its utilization for respirator cartridges. Activated carbon was impregnated with a nickel nitrate catalyst precursor and carbonnanofibers (CNF were deposited directly on the AC surface using catalytic chemical vapor deposition. Deposited CNFs on catalyst particles in AC micropores, were activated by CO2 to recover the surface area and micropores.Surface and textural characterizations of the prepared composites were investigated using Brunauer, Emmett andTeller’s (BET technique and electron microscopy respectively. Prepared composite adsorbent was tested forbenzene, toluene and xylene (BTX adsorption and then employed in an organic respirator cartridge in granularform. Adsorption studies were conducted by passing air samples through the adsorbents in a glass column at an adjustable flow rate. Finally, any adsorbed species not retained by the adsorbents in the column were trapped in a charcoal sorbent tube and analyzed by gas chromatography. CNFs with a very thin diameter of about 10-20 nmwere formed uniformly on the AC/CNF. The breakthrough time for cartridges prepared with CO2 activated AC/CNF was 117 minutes which are significantly longer than for those cartridges prepared with walnut shell- based activated carbon with the same weight of adsorbents. This study showed that a granular form CO2 activated AC/CNF composite could be a very effective alternate adsorbent for respirator cartridges due to its larger adsorption capacities and lower weight.

EFFECT OF IMPREGNATION PROCEDURE OF Pt/γ-Al2O3 CATALYSTS UPON CATALYTIC OXIDATION OF CO

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Triyono Triyono

2010-06-01

Full Text Available The oxidation of carbon monoxide by oxygen using two catalysts prepared by two different methods has been investigated. In the first method, catalyst prepared by immersing γ-Al2O3 into the hexa-chloroplatinic acid solution at 80oC for 4 h, resulted Pt/γ-Al2O3 catalyst having platinum highly dispersed on the support. While that of immersing γ-Al2O3 in the hexa-chloroplatinic acid solution at room temperature for 12 h, produced Pt/ γ-Al2O3 catalyst where platinum dispersion was much lower. Catalytic activity test showed that platinum well dispersed on the support enhanced the activity of oxidation of carbon monoxide. The platinum impregnated at room temperature resulted in the poor activity.   Keyword: Catalyst, CO Oxidation, Platinum.

Mercury adsorption properties of sulfur-impregnated adsorbents

Science.gov (United States)

Hsi, N.-C.; Rood, M.J.; Rostam-Abadi, M.; Chen, S.; Chang, R.

2002-01-01

Carbonaceous and noncarbonaceous adsorbents were impregnated with elemental sulfur to evaluate the chemical and physical properties of the adsorbents and their equilibrium mercury adsorption capacities. Simulated coal combustion flue gas conditions were used to determine the equilibrium adsorption capacities for Hg0 and HgCl2 gases to better understand how to remove mercury from gas streams generated by coal-fired utility power plants. Sulfur was deposited onto the adsorbents by monolayer surface deposition or volume pore filling. Sulfur impregnation increased the total sulfur content and decreased the total and micropore surface areas and pore volumes for all of the adsorbents tested. Adsorbents with sufficient amounts of active adsorption sites and sufficient microporous structure had mercury adsorption capacities up to 4,509 ??g Hg/g adsorbent. Elemental sulfur, organic sulfur, and sulfate were formed on the adsorbents during sulfur impregnation. Correlations were established with R2>0.92 between the equilibrium Hg0/HgCl2 adsorption capacities and the mass concentrations of elemental and organic sulfur. This result indicates that elemental and organic sulfur are important active adsorption sites for Hg0 and HgCl2.

Preparation of Palladium-Impregnated Ceria by Metal Complex Decomposition for Methane Steam Reforming Catalysis

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Worawat Wattanathana

2017-01-01

Full Text Available Palladium-impregnated ceria materials were successfully prepared via an integrated procedure between a metal complex decomposition method and a microwave-assisted wetness impregnation. Firstly, ceria (CeO2 powders were synthesized by thermal decomposition of cerium(III complexes prepared by using cerium(III nitrate or cerium(III chloride as a metal source to form a metal complex precursor with triethanolamine or benzoxazine dimer as an organic ligand. Palladium(II nitrate was consequently introduced to the preformed ceria materials using wetness impregnation while applying microwave irradiation to assist dispersion of the dopant. The palladium-impregnated ceria materials were obtained by calcination under reduced atmosphere of 10% H2 in He stream at 700°C for 2 h. Characterization of the palladium-impregnated ceria materials reveals the influences of the metal complex precursors on the properties of the obtained materials. Interestingly, the palladium-impregnated ceria prepared from the cerium(III-benzoxazine dimer complex revealed significantly higher BET specific surface area and higher content of the more active Pdδ+ (δ > 2 species than the materials prepared from cerium(III-triethanolamine complexes. Consequently, it exhibited the most efficient catalytic activity in the methane steam reforming reaction. By optimization of the metal complex precursors, characteristics of the obtained palladium-impregnated ceria catalysts can be modified and hence influence the catalytic activity.

The application and study of an oxide-impregnated nickel-matrix cathode for Beijing proton linac

International Nuclear Information System (INIS)

Xia Dehong; Shi Rongjian

1996-01-01

A low power consumption oxide-impregnated nickel-matrix cathode used in the Duoplasmatron ion source of the Beijing Proton Linac (BPL) is presented. Its structure, treatment process of nickel-foam rubber on metal matrix surface and manufacture of dip coating carbonate are briefly introduced. The activation method and experiment results of the cathode are described. The principal factors which influence the cathode lifetime are discussed. The lifetime of the cathode is up to 2110 h while the extracted pulsed beam current is about 200 mA

Process for making 90 degree K. superconductors by impregnating cellulosic article with precursor solution

International Nuclear Information System (INIS)

Bolt, J.D.; Subramanian, M.A.

1991-01-01

This patent describes an improved process for preparing a shaped article of a superconducting composition having the formula MBa 2 Cu 3 O x wherein; M is selected from the group consisting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; x is from about 6.5 to about 7.0; the composition having a superconducting transition temperature of about 90 K. It comprises: forming in acetic acid a mixture of M(C 2 H 3 O 2 ) 3 , barium acetate and copper acetate in an atomic ratio of M:Ba:Cu of about 1:2:3; heating the resulting mixture to boiling, and adding sufficient formic acid to dissolve any undissolved starting material while continuing to boil the solution; contacting an article of cellulose material with the solution thereby impregnating the article with the solution, the article having the shape desired; removing excess solution from the resulting impregnated article of cellulose material and drying the impregnated article; heating the impregnated article of cellulose material to a temperature from about 850 degree C to about 925 degree C in an oxygen-containing atmosphere for a time sufficient to form MBa 2 Cu 3 O y , where y is from about 6.0 to about 6.5, the heating effecting carbonization of the cellulose material and oxidization of carbon without ignition; and maintaining the resulting article in an oxygen-containing atmosphere while cooling for a time sufficient to obtained the desired product

Chlorinated phenol removal from aqueous media by tea (Camellia sinensis) leaf waste tailored activated carbon

Science.gov (United States)

Joseph, C. G.; Anisuzzaman, S. M.; Daud, W. M. A. W.; Krishnaiah, D.; Ng, K. A.

2017-06-01

In this study, activated carbons (ACs) wereprepared from tea leaves by using a two-stage self-generated atmosphere method. The process was done by semi-carbonizing the precursor at 300 °C for 1 h, followed by the impregnation of the resulting char at 85 °C for 4 h and finally activation at 500 °C for 2 h. The semi-carbonised samples were impregnated with different ratios of zinc chloride (ZnCl2) and their physicochemical effect was studied. The prepared ACs underwent several aspects of both, chemical and physical characterizations, such as the percentage of yield, moisture content, ash content, pH, porosity, adsorption capacity of 2,4-dichlorophenol (2,4-DCP), surface area, porosity, morphology and surface chemistry studies. It was found that sample AC2, with an impregnation ratio of 2:1 was the best AC produced in this study. The maximum Brunauer, Emmett and Teller surface area of AC2 was found to be 695 m2/g. Langmuir, Freundlich and Temkin isotherm models were used to examine the experimental isotherms while the kinetic data was analyzed using the pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models. The 2,4-DCP adsorption isotherm results complied well to the Langmuir isotherm for the equilibrium data while the adsorption kinetic data fitted well to the pseudo-second order model, indicating that chemisorption by valency forces via the sharing (covalent bond) or exchanging of electrons between the AC and the 2,4-DCP molecules were mainly responsible for the adsorption process. From these findings, it is concluded that tea leaves can be used as a low cost precursor for the removal of 2,4-DCP in aqueous medium.

Characterization of mesoporous carbon prepared from date stems by H3PO4 chemical activation

International Nuclear Information System (INIS)

Hadoun, H.; Sadaoui, Z.; Souami, N.; Sahel, D.; Toumert, I.

2013-01-01

The present work was focused on the determination of texture, morphology, crystanillity and oxygenated surface groups characteristics of an activated carbon prepared from date stems. Chemical activation of this precursor at different temperatures (450, 550 and 650 °C) was adopted using phosphoric acid as dehydrating agent at (2/1) impregnation ratio. Fourier transform infrared spectroscopy study was carried out to identify surface groups in date stems activated carbons. The microscopic structure was examined by nitrogen adsorption at 77 K. The interlayer spacing (d 200 and d 100 ), stack height (L c ), stack width (L a ) and effective dimension L of the turbostratic crystallites (microcrystallite) in the date stems activated carbons were estimated from X-ray diffraction data (XRD). Results yielded a surface area, S BET , and total pore volume of 682, 1455, 1319 m 2 /g and 0,343, 1,045 and 0.735 cm 3 /g, for the carbon prepared at 450, 550 and 650 °C, respectively. Scanning electron microscopy exhibits a highly developed porosity which is in good agreement with the porous texture derived from gas adsorption data and these results confirm that the activated carbon is dominated by network of slit-shaped mesopores morphology and in some cases by varied micropores morphologies.

Removal of arsenic and methylene blue from water by granular activated carbon media impregnated with zirconium dioxide nanoparticles

International Nuclear Information System (INIS)

Sandoval, Robert; Cooper, Anne Marie; Aymar, Kathryn; Jain, Arti; Hristovski, Kiril

2011-01-01

Highlights: → The morphology, content and distribution of ZrO 2 nanoparticles inside the pores of GAC are affected by the type of GAC. → Lignite ZrO 2 -GAC exhibited Zr content of 12%, while bituminous based ZrO 2 -GAC exhibited Zr content of 9.5%. → The max. adsorption capacities under equilibrium conditions in 5 mM NaHCO 3 buffered water matrix were ∼8.6 As/g Zr and ∼12.2 mg As/g Zr at pH = 7.6. → The max. adsorption capacities under equilibrium conditions in NSF 53 Challenge water matrix while ∼1.5 mg As/g Zr and ∼3.2 mg As/g Zr at pH = 7.6. → Introduction of nanoparticles did not impact the MB adsorption capacity of the lignite ZrO 2 -GAC, while the one of bituminous ZrO 2 -GAC decreased. - Abstract: This study investigated the effects of in situ ZrO 2 nanoparticle formation on properties of granulated activated carbon (GAC) and their impacts on arsenic and organic co-contaminant removal. Bituminous and lignite based zirconium dioxide impregnated GAC (Zr-GAC) media were fabricated by hydrolysis of zirconium salt followed by annealing of the product at 400 o C in an inert environment. Media characterization suggested that GAC type does not affect the crystalline structure of the resulting ZrO 2 nanoparticles, but does affect zirconium content of the media, nanoparticle morphology, nanoparticle distribution, and surface area of Zr-GAC. The arsenic removal performance of both media was compared using 5 mM NaHCO 3 buffered ultrapure water and model groundwater containing competing ions, both with an initial arsenic C 0 ∼ 120 μg/L. Experimental outcomes suggested favorable adsorption energies and higher or similar adsorption capacities than commercially available or experimental adsorbents when compared on the basis of metal content. Short bed adsorber column tests showed that arsenic adsorption capacity decreases as a result of kinetics of competing ions. Correlation between the properties of the media and arsenic and methylene blue removal

Development of activated carbon derived from banana peel for CO{sub 2} removal

Energy Technology Data Exchange (ETDEWEB)

Borhan, Azry; Thangamuthu, Subhashini; Ramdan, Amira Nurain [Chemical Engineering Department Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 32610, Perak (Malaysia); Taha, Mohd Faisal [Fundamental and Applied Sciences Department Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 32610, Perak (Malaysia)

2015-08-28

This research work highlights on the constraints involved in the preparation of the banana peel bio-sorbent, such as impregnation ratio, activation temperature and period of activation for reducing carbon dioxide (CO{sub 2}) in the atmosphere. Micromeritics ASAP 2020 and Field Emission Scanning Electron Microscope (FESEM) were used in identifying the best sample preparation method with the largest surface area which directly contributes to the effectiveness of adsorbent in removing CO{sub 2}. Sample A10 was identified to yield activated carbon with the largest surface area (260.3841 m{sup 2}/g), total pore volume (0.01638 cm{sup 3}/g) and pore diameter (0.2508 nm). Through nitrogen adsorption-desorption isotherm analysis, the existence of sub-micropores was proven when a combination of Type-I and Type-II isotherms were exhibited by the activated carbon produced. The results from the final adsorption test found that the material synthesized from the above mentioned parameter is capable of removing up to 1.65% wt of CO{sub 2} through adsorption at 25°C, suggesting that it can be effectively used as an adsorption material.

Comparison of the compressive strength of impregnated and nonimpregnated eucalyptus subjected to two different pressures and impregnation times

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Waldemir Rodrigues

2004-06-01

Full Text Available The durability of wood is affected by several factors. For this reason, much research has been done on a variety of chemical compounds for impregnating wood, aimed at preserving it while simultaneously improving its properties. Recent studies of the properties of impregnated wood have demonstrated the possibility of substantially improving its mechanical characteristics. Thus, the purpose of this work was to compare the strength to parallel compression of wooden fibers (Eucalyptus grandis, both nonimpregnated and impregnated with a monocomponent resin, from the standpoint of pressure and impregnation time, aiming at its structural utilization. The results demonstrate that the compressive strength of impregnated test specimens is greater than that of nonimpregnated ones, indicating that monocomponent polyurethane resin can be considered suitable for impregnating wood, since it increases the compressive strength of eucalyptus.

A study on the safety of spent fuel management

International Nuclear Information System (INIS)

Park, Seong Won; Chun, Kwan Sik; Lee, Hoo Kuen; Park, Kuen Il; Jung, Myung Soo; Kim, You Sun

1992-03-01

In order to establish the effective removal system of radioactive iodine compound generated from the nuclear facilities, study on adsorption and desorption of organic iodine by impregnated active carbon was carried out. Physical characteristics of impregnated active carbon was identified, and the adsorption of water vapor and the methyl iodide adsorption and desorption characteristics by impregnated active carbon were studied. Also, the weathering effects on impregnated active carbon was analyzed to evaluate the long-term capacity of impregnated active carbon. In addition, the existing test facility of impregnated active carbon was partly updated by incorporating sophisticated temperature and humidity controling system. (Author)

Preparation and Characterization of Various Activated Carbons Derived From Mixed Precursors Using Phosphoric Acid

International Nuclear Information System (INIS)

Daifullah, A.A.M.; Sharaf El-Deen, S.E.A.; Elkhalafawy, A.; Shehata, F.A.; Mahmoud, W.H.

2008-01-01

Rice straw (RS) and rice husk (RH), a low-cost agricultural by-products, have been used as a mixed precursor (i.e., RS mixed with RH in 1:1; 1:3 and 3:1 ratios) for the production of novel carbons using phosphoric acid as chemical activation. The raw materials were impregnated with 50% and 70% H 3 PO 4 followed by activation at 500 degree C. The latter proved to be the most effective in producing active carbon with good adsorptive capacity. The resulting carbons were characterized by elemental analysis, infrared spectroscopy, density, SEM and S BET . In general, the resulting carbons showed reasonable surface areas with mainly micropore structure. The adsorption capacity was demonstrated by the isotherms of methylene blue (MB), phenol and iodine from aqueous solution. The adsorption data was found to conform with the Langmuir equation with the concentration range studied, and the monolayer coverage was determined for each of the samples. It was found that surface area is mainly attributed to micropore volume so that phenol adsorption and iodine number correspond well with surface area determined by nitrogen adsorption

Recycling of impregnated wood and impregnating agents - combustion plant technology; Kyllaestetyn puutavaran ja kyllaestysaineiden kierraetys - polttolaitostekniikka

Energy Technology Data Exchange (ETDEWEB)

Syrjaenen, T.; Kangas, E. [Kestopuu Oy, Helsinki (Finland)

2000-07-01

It has been estimated that in the 20th century it is possible to recycle about 70 000 m{sup 3} of impregnated wood, corresponding to about 48 % of the total amount of annually demolished impregnated wood. The amount is estimated to grow up to 130 000 m{sup 3} in 2015 (about 65% of demolished impregnated wood). In the beginning half of the recyclable impregnated wood is poles, but the share of sawn timber will increase as the time goes by. The poles and pieces of them are demolished and transported to an intermediate storage e.g. on the yard of an electricity supply company, from which they can be fetched in larger quantities. Even wood impregnation plant can act as intermediate storage sites. Collection points for impregnated construction timber can be established on timer sales companies, but most of it will be collected at waste processing sites. The economy of impregnated wood recycling chain depends on the sales income of generated energy. Calculations show that collection, transportation and processing costs can be covered with the sales of impregnated wood for energy generation and with recycling fees. The recycling fee for sawn timber would be 20 FIM/m{sup 3} and that for poles 64 FIM/m{sup 3}. In 2001 recycling fees were set for impregnated wood, the fees being 11 FIM/m{sup 3} for sawn timber and 42 FIM/m{sup 3} for poles. Collected impregnated wood can be crushed with either fixed or movable crushers used for crushing of waste wood. The impurities of wood (bolts, nails, stones, etc.), large dimensions of wood, in- homogenous material and dust require special features for the crushing equipment. Crushing device can be equipped with feeding crane and saw for processing of large-dimension wood, and metal detectors and magnetic separators if needed, but the large metal scrap has to be removed before crushing. At present in Finland there is not a combustion plant capable for combustion of impregnated wood without any modification. Improvements of flue gas

Thermodynamic Study of Adsorption of Phenol, 4-Chlorophenol, and 4-Nitrophenol on Activated Carbon Obtained from Eucalyptus Seed

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Nelson Giovanny Rincón-Silva

2015-01-01

Full Text Available Activated carbons from shell eucalyptus (Eucalyptus globulus were prepared by chemical activation through impregnation with solutions of two activators: sulfuric acid and sodium hydroxide, the surface areas for activated carbons with base were 780 and 670 m2 g−1 and the solids activated with acid were 150 and 80 m2 g−1. These were applying in adsorption of priority pollutants: phenol, 4-nitrophenol, and 4-chlorophenol from aqueous solution. Activated carbon with the highest adsorption capacity has values of 2.12, 2.57, and 3.89 on phenol, 4-nitrophenol, and 4-chlorophenol, respectively, and was activated with base. In general, all carbons adsorption capacity was given in the following order: 4-chlorophenol > 4-nitrophenol > phenol. Adsorption isotherms of phenols on activated carbons were fitted to the Langmuir, Freundlich, and Dubinin-Radusckevisch-Kanager models, finding great association between them and experimental data. A thermodynamic study was performed, the exothermic nature and spontaneous nature of the adsorption process were confirmed, and the favorability of adsorption on activated carbons with NaOH was confirmed by energy relations and concluded that the adsorption process of phenolic compounds from the activated carbon obtained is physical. The pH of solutions and pH at point of zero charge of the solid play an important role in the adsorption process.

Durability of Gamma Irradiated Polymer Impregnated Blended Cement Pastes

International Nuclear Information System (INIS)

Khattab, M.M.; Abdel-Rahman, H.A.; Younes, M.M.

2010-01-01

This study is focusing on durability and performance of the neat blended cement paste as well as those of the polymer-impregnated paste towards seawater and various concentrations of magnesium sulfate solutions up to 6 months of curing. The neat blended cement paste is prepared by a partial substitution of ordinary Portland cement with 5% of active rice husk ash (RHA). These samples were cured under tap water for 7 days. Similar samples were impregnated with unsaturated polyester resin (UPE) and subjected to various doses of gamma rays ranging from 10 to 50 kGy. The results showed that the irradiated impregnated specimens gave higher values of compressive strength than the neat blended cement paste specimens. On immersing the neat blended cement specimens and polymer impregnated specimens especially that irradiated at 30 kGy in seawater and different concentrations of magnesium sulfate solutions up to 6 months of curing, the results showed that the polymer impregnated blended cement (OPC-RHA-UPE) paste have a good resistance towards aggressive media as compared to the neat blended cement (OPC-RHA) paste. The results also indicated that the sea water has a greater corrosive effect than the magnesium sulfate solutions. These results were confirmed by scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP)

Method of making a multi-electrode double layer capacitor having single electrolyte seal and aluminum-impregnated carbon cloth electrodes

Science.gov (United States)

Farahmandi, C. Joseph; Dispennette, John M.; Blank, Edward; Kolb, Alan C.

2002-09-17

A single cell, multi-electrode high performance double layer capacitor includes first and second flat stacks of electrodes adapted to be housed in a closeable two-part capacitor case which includes only a single electrolyte seal. Each electrode stack has a plurality of electrodes connected in parallel, with the electrodes of one stack being interleaved with the electrodes of the other stack to form an interleaved stack, and with the electrodes of each stack being electrically connected to respective capacitor terminals. A porous separator is positioned against the electrodes of one stack before interleaving to prevent electrical shorts between the electrodes. The electrodes are made by folding a compressible, low resistance, aluminum-impregnated carbon cloth, made from activated carbon fibers, around a current collector foil, with a tab of the foils of each electrode of each stack being connected in parallel and connected to the respective capacitor terminal. The height of the interleaved stack is somewhat greater than the inside height of the closed capacitor case, thereby requiring compression of the interleaved electrode stack when placed inside of the case, and thereby maintaining the interleaved electrode stack under modest constant pressure. The closed capacitor case is filled with an electrolytic solution and sealed. A preferred electrolytic solution is made by dissolving an appropriate salt into acetonitrile (CH.sub.3 CN). In one embodiment, the two parts of the capacitor case are conductive and function as the capacitor terminals.

Porous carbon from local coconut shell char by CO2 and H2O activation in the presence of K2CO3

Science.gov (United States)

Vi, Nguyen Ngoc Thuy; Truyen, Dang Hai; Trung, Bien Cong; An, Ngo Thanh; Van Dung, Nguyen; Long, Nguyen Quang

2017-09-01

Vietnamese coconut shell char was activated by steam and carbon dioxide at low temperatures with the presence of K2CO3 as a catalyst. The effects of process parameters on adsorption capability of the product including different ratio of impregnation of activation agents, activation temperature, activation time were investigated in this study. Iodine number, methylene blue adsorption capacity, specific surface area and pore size distribution were measured to assess the properties of the activated carbon. Accordingly, the porous carbon was applied for toluene removal by adsorption technology. Significant increases in specific surface area and the toluene adsorption capacity were observed when the coconut shell char was activated in CO2 flow at 720 °C for 150 minutes and the K2CO3/char weight ratio of 0.5.

NiMo-sulfide supported on activated carbon to produce renewable diesel

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Nancy Y Acelas

2017-03-01

Full Text Available Due to their weak polarity and large surface area, activated carbon supports have the potential to enhance the dispersion of metal-sulfides. It is expected that the absence of a strong metal-support interaction can result in the formation of a very active and stable Ni-Mo-S phase. In this study, catalysts with different amounts of nickel and molybdenum supported on a commercial activated carbon were prepared by a co-impregnation method and characterized by BET, XRF, and SEM techniques. The catalytic activity for hydroprocessing of Jatropha oil was evaluated in a batch reactor, and the composition of the liquid and gaseous products were determined. Results showed that gaseous products are mainly composed of high amounts of propane and small amounts of other light hydrocarbons (C1 to C5. Liquid hydrocarbon products consisted of a mixture containing mainly n-paraffins of C15-C18 and some oxygenated compounds. The catalysts with a mass fraction of 3 % Ni, 15 % Mo (Ni3Mo15/AC presented the highest selectivity toward C17-C18 hydrocarbons, with a product distribution similar to a commercial alumina-supported Ni-Mo-S catalyst.

Study on the associated removal of pollutants from coal-firing flue gas using biomass activated carbon pellets

Energy Technology Data Exchange (ETDEWEB)

Wang, Cuiping; Yuan, Wanli [Qingdao Univ., Shandong (China). Electrical and Mechanical Engineering College; Qi, Haiying [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering

2013-07-01

A pilot-scale multi-layer system was developed for the adsorption of SO{sub 2}/NO{sub x}/Hg from flue gas (real flue gases of an heating boiler house) at various operating conditions, including operating temperature and activated carbon materials. Excellent SO{sub 2}/NO{sub x}/Hg removal efficiency was achieved with the multi-layer design with carbons pellets. The SO{sub 2} removal efficiency achieved with the first layer adsorption bed clearly decreased as the operating temperature was increased due to the decrease of physisorption performance. The NO{sub x} removal efficiency measured at the second layer adsorption bed was very higher when the particle carbon impregnated with NH{sub 3}. The higher amounts of Hg absorbed by cotton-seed-skin activated carbon (CSAC) were mainly contributed by chlorinated congeners content. The simultaneously removal of SO{sub 2}/NO{sub x}/Hg was optimization characterized with different carbon layer functions. Overall, The alkali function group and chloride content in CSAC impelled not only the outstanding physisorption but also better chemisorptions. The system for simultaneously removal of multi-pollutant-gas with biomass activated carbon pellets in multi-layer reactor was achieved and the removal results indicated was strongly depended on the activated carbon material and operating temperature.

Magnetic Fe2MO4 (M:Fe, Mn) activated carbons: Fabrication, characterization and heterogeneous Fenton oxidation of methyl orange

International Nuclear Information System (INIS)

Nguyen, Thi Dung; Phan, Ngoc Hoa; Do, Manh Huy; Ngo, Kim Tham

2011-01-01

We present a simple and efficient method for the fabrication of magnetic Fe 2 MO 4 (M:Fe and Mn) activated carbons (Fe 2 MO 4 /AC-H, M:Fe and Mn) by impregnating the activated carbon with simultaneous magnetic precursor and carbon modifying agent followed by calcination. The obtained samples were characterized by nitrogen adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), and the catalytic activity in heterogeneous Fenton oxidation of methyl orange (MO) was evaluated. The resulting Fe 2 MnO 4 /AC-H showed higher catalytic activity in the methyl orange oxidation than Fe 3 O 4 /AC-H. The effect of operational parameters (pH, catalyst loading H 2 O 2 dosage and initial MO concentration) on degradation performance of the oxidation process was investigated. Stability and reusability of selected catalyst were also tested.

Study of desorption of methyl iodide from activated carbon impregnated by TEDA

International Nuclear Information System (INIS)

Yue Longqing; Luo Deli; Yue Ziyu

2013-01-01

The capability of iodine retention is an important parameter of solid sorbent, iodine could be desorbed from activated carbon once the parameter doesn't meet requirement. This work discussed the effects of nitrogen flow rate, dipping in water, temperature and K + on the iodine retention. The results show, the quantities of iodine released increase to 3.15 times when nitrogen flow rates increase from 0.1 m 3 /h to 1.5 m 3 /h; methyl iodine molecules are desorbed after half of an hour's dipping in water with no notable change observed thereafter to the desorption capacity at l.5 h, 2 h, 3 h, 4 h respectively; there was no release of iodine below 80 ℃; K + play a positive role for retention of iodine species; and that the quantities of methyl iodine released with 0.06 g KCl account for 56% of that without KCl. (authors)

Activity of Cu-activated carbon fiber catalyst in wet oxidation of ammonia solution.

Science.gov (United States)

Hung, Chang-Mao

2009-07-30

Aqueous solutions of 200-1000 mg/L of ammonia were oxidized in a trickle-bed reactor using Cu-activated carbon fiber (ACF) catalysts, which were prepared by incipient wet impregnation with aqueous solutions of copper nitrate that was deposited on ACF substrates. The results reveal that the conversion of ammonia by wet oxidation in the presence of Cu-ACF catalysts was a function of the metal loading weight ratio of the catalyst. The total conversion efficiency of ammonia was 95% during wet oxidation over the catalyst at 463 K at an oxygen partial pressure of 3.0 MPa. Moreover, the effect of the initial concentration of ammonia and the reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid space velocity of less than 3.0 h(-1).

Activity of Cu-activated carbon fiber catalyst in wet oxidation of ammonia solution

International Nuclear Information System (INIS)

Hung, Chang-Mao

2009-01-01

Aqueous solutions of 200-1000 mg/L of ammonia were oxidized in a trickle-bed reactor using Cu-activated carbon fiber (ACF) catalysts, which were prepared by incipient wet impregnation with aqueous solutions of copper nitrate that was deposited on ACF substrates. The results reveal that the conversion of ammonia by wet oxidation in the presence of Cu-ACF catalysts was a function of the metal loading weight ratio of the catalyst. The total conversion efficiency of ammonia was 95% during wet oxidation over the catalyst at 463 K at an oxygen partial pressure of 3.0 MPa. Moreover, the effect of the initial concentration of ammonia and the reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid space velocity of less than 3.0 h -1 .

Investigation of the metabolic consequences of impregnating spinach leaves with trehalose and applying a pulsed electric field.

Science.gov (United States)

Dymek, Katarzyna; Panarese, Valentina; Herremans, Els; Cantre, Dennis; Schoo, Rick; Toraño, Javier Sastre; Schluepmann, Henriette; Wadso, Lars; Verboven, Pieter; Nicolai, Bart M; Dejmek, Petr; Gómez Galindo, Federico

2016-12-01

The impregnation of leafy vegetables with cryoprotectants using a combination of vacuum impregnation (VI) and pulsed electric fields (PEF) has been proposed by our research group as a method of improving their freezing tolerance and consequently their general quality after thawing. In this study, we have investigated the metabolic consequences of the combination of these unit operations on spinach. The vacuum impregnated spinach leaves showed a drastic decrease in the porosity of the extracellular space. However, at maximum weight gain, randomly located air pockets remained, which may account for oxygen-consuming pathways in the cells being active after VI. The metabolic activity of the impregnated leaves showed a drastic increase that was further enhanced by the application of PEF to the impregnated tissue. Impregnating the leaves with trehalose by VI led to a significant accumulation of trehalose-6-phosphate (T6P), however, this was not further enhanced by PEF. It is suggested that the accumulation of T6P in the leaves may increase metabolic activity, and increase tissue resistance to abiotic stress. Copyright © 2016 Elsevier B.V. All rights reserved.

The relation between inversion enthalpy and adsorption parameters for an activated carbon in aqueous Pb2+ solutions

International Nuclear Information System (INIS)

Giraldo, Liliana; Moreno, Juan Carlos

2006-01-01

We report the preparation of an activated carbon obtained by impregnation of mineral carbon samples with a phosphoric acid solution (50%).The obtained material, exhibits a superficial area of 586 m 2 .g -1 and a total pore volume of 0.37 cm 3 g -1 . With respect to the chemical properties, the activated carbon shows an increased number of acidic sites (0.92 meq g -l ) compared to basic sites (0.63 meq g-1) which yields a material with almost neutral characteristics (PHpzc: 7.4). At a pH: 4.0 the amount of Pb 2 + absorbed and the immersion enthalpy values for the activated carbon reached a maximum with values of 15.7 mg -1 y 27.6 Jg -1 respectively. It was established that similar behaviour occurs for the two properties, absorption and immersion enthalpy, as a function of pH. In addition, a second order function that relates the adsorption constant and immersion enthalpy, and the adsorption constant and pH of the solution are presented

Removal of Hexavalent Chromium by Adsorption on Microwave Assisted Activated Carbon Prepared from Stems of Leucas Aspera

Science.gov (United States)

Shanmugalingam, A.; Murugesan, A.

2018-05-01

This study reports adsorption of Cr(VI) ions from aqueous solution using activated carbon that was prepared from stems of Leucas aspera. Eight hundred and fifty watts power of microwave radiation, 12 min of radiation time, 60% of ZnCl2 solution and 24 h of impregnation time are the optimal parameters to prepare efficient carbon effective activated carbon. It was designated as MWLAC (Microwave assisted Zinc chloride activated Leucas aspera carbon). Various adsorption characteristics such as dose of the adsorbent, agitation time, initial Cr(VI) ion concentration, pH of the solution and temperature on adsorption were studied for removal of Cr(VI) ions from aqueous solution by batch mode. Also the equilibrium adsorption was analyzed by the Langmuir, Freundlich, Tempkin and D-R isotherm models. The order of best describing isotherms was given based on R2 value. The pseudo-second-order kinetic model best fitted with the Cr(VI) adsorption data. Thermodynamic parameters were also determined and results suggest that the adsorption process is a spontaneous, endothermic and proceeded with increased randomness.

The relation between immersion enthalpy and adsorption parameters for an activated carbon in aqueous Pb2+solutions

International Nuclear Information System (INIS)

Girado, Liliana; Moreno, Juan Carlos

2006-01-01

We report the preparation of an activated carbon obtained by impregnation of mineral carbon samples with phosphoric acid solution (50%). the obtained material, exhibits a superficial area of 586 m 2 .g -1 and a total pore volume of 0,37 cm 3 g -1 . with respect to the chemical properties, the activated carbon shows an increased number of acidic sites (0,92 meq g -1 ) compared to basic sites (0,63 meq g -1 ) which yields a material with almost neutral characteristics (pH p zc: 7,4). At a pH: 4.0 the amount of pb2+ absorbed and the immersion enthalpy values for the activated carbon reached maxim with values of 15.7 mg -1 y 27,6 Jg -1 respectively. it was established that similar behavior occurs for the two properties, absorption and immersion enthalpy, as a function of pH. in addition, a second order function that relates the adsorption constant and immersion enthalpy, and the adsorption constant and ph of the solution are presented

Desorption, partitioning, and dechlorination characteristics of PCBs in sediments in interaction with reactive activated carbon

International Nuclear Information System (INIS)

Choi, Hyeok; Lawal, Wasiu; Al-Abed, Souhail R.

2015-01-01

Highlights: • Problematic aged real PCBs-contaminated sediment (WHS) was examined. • Performance of reactive activated carbon (RAC) impregnated with Pd–ZVI was tested. • Fate and transport of PCBs bound to WHS in the presence of RAC was fully traced. • Direct mixing configuration was compared with compartment configuration. • Results reflected real world complexities associated with slow desorption of PCBs. - Abstract: Sediment (WHS) in Waukegan Harbor, Illinois, heavily contaminated and aged with polychlorinated biphenyls (PCBs), was treated with reactive activated carbon (RAC) impregnated with palladized iron nanoparticles. Lab test proceeded in a direct mixing configuration of RAC and WHS. A compartment configuration, where RAC was physically separated from WHS, was also designed to trace the sequential transport and fate of PCBs, including desorption, adsorption, dechlorination, and re-partitioning. PCBs, once desorbed from WHS, were immediately sequestrated to RAC and subject to dechlorination. Direct mixing of WHS with RAC was one-order of magnitude more effective for dechlorination than compartment configuration. Compared to their desorption-followed by-adsorption route, direct physical contact of RAC with PCBs bound to WHS exhibited negligible contribution to the availability of PCBs for dechlorination reaction. Addition of RAC even in compartment configuration facilitated PCBs desorption from WHS. However, slow desorption of PCBs limited overall performance, resulting in a five-order of magnitude lower dechlorination yield when compared with treatment of purely aqueous PCBs. The low dechlorination yield reflected real world complexities in treating 3.19% organic carbon-containing WHS aged with PCBs for 40 years. These observations were further supported when compared with results on clean Cesar Creek sediment spiked with 2-chlorinated biphenyls

Desorption, partitioning, and dechlorination characteristics of PCBs in sediments in interaction with reactive activated carbon

Energy Technology Data Exchange (ETDEWEB)

Choi, Hyeok, E-mail: hchoi@uta.edu [Department of Civil Engineering, The University of Texas at Arlington, 416 Yates Street, Arlington, TX 76019-0308 (United States); Environmental and Earth Sciences Program, The University of Texas at Arlington, 500 Yates Street, Arlington, TX 76019-0049 (United States); Lawal, Wasiu [Environmental and Earth Sciences Program, The University of Texas at Arlington, 500 Yates Street, Arlington, TX 76019-0049 (United States); Al-Abed, Souhail R. [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268 (United States)

2015-04-28

Highlights: • Problematic aged real PCBs-contaminated sediment (WHS) was examined. • Performance of reactive activated carbon (RAC) impregnated with Pd–ZVI was tested. • Fate and transport of PCBs bound to WHS in the presence of RAC was fully traced. • Direct mixing configuration was compared with compartment configuration. • Results reflected real world complexities associated with slow desorption of PCBs. - Abstract: Sediment (WHS) in Waukegan Harbor, Illinois, heavily contaminated and aged with polychlorinated biphenyls (PCBs), was treated with reactive activated carbon (RAC) impregnated with palladized iron nanoparticles. Lab test proceeded in a direct mixing configuration of RAC and WHS. A compartment configuration, where RAC was physically separated from WHS, was also designed to trace the sequential transport and fate of PCBs, including desorption, adsorption, dechlorination, and re-partitioning. PCBs, once desorbed from WHS, were immediately sequestrated to RAC and subject to dechlorination. Direct mixing of WHS with RAC was one-order of magnitude more effective for dechlorination than compartment configuration. Compared to their desorption-followed by-adsorption route, direct physical contact of RAC with PCBs bound to WHS exhibited negligible contribution to the availability of PCBs for dechlorination reaction. Addition of RAC even in compartment configuration facilitated PCBs desorption from WHS. However, slow desorption of PCBs limited overall performance, resulting in a five-order of magnitude lower dechlorination yield when compared with treatment of purely aqueous PCBs. The low dechlorination yield reflected real world complexities in treating 3.19% organic carbon-containing WHS aged with PCBs for 40 years. These observations were further supported when compared with results on clean Cesar Creek sediment spiked with 2-chlorinated biphenyls.

Characterization of mesoporous carbon prepared from date stems by H{sub 3}PO{sub 4} chemical activation

Energy Technology Data Exchange (ETDEWEB)

Hadoun, H., E-mail: hhadoun@hotmail.com [Nuclear Research Center, 2 Bd Frantz Fanon, Algiers (Algeria); Laboratory of Reaction Genius, Mechanical and Processes Genius Faculty, University of Sciences and Technology Houari – Boumediene, BP n°32, El alia, bab ezzouar, 16111 Algiers (Algeria); Sadaoui, Z. [Laboratory of Reaction Genius, Mechanical and Processes Genius Faculty, University of Sciences and Technology Houari – Boumediene, BP n°32, El alia, bab ezzouar, 16111 Algiers (Algeria); Souami, N.; Sahel, D.; Toumert, I. [Nuclear Research Center, 2 Bd Frantz Fanon, Algiers (Algeria)

2013-09-01

The present work was focused on the determination of texture, morphology, crystanillity and oxygenated surface groups characteristics of an activated carbon prepared from date stems. Chemical activation of this precursor at different temperatures (450, 550 and 650 °C) was adopted using phosphoric acid as dehydrating agent at (2/1) impregnation ratio. Fourier transform infrared spectroscopy study was carried out to identify surface groups in date stems activated carbons. The microscopic structure was examined by nitrogen adsorption at 77 K. The interlayer spacing (d{sub 200} and d{sub 100}), stack height (L{sub c}), stack width (L{sub a}) and effective dimension L of the turbostratic crystallites (microcrystallite) in the date stems activated carbons were estimated from X-ray diffraction data (XRD). Results yielded a surface area, S{sub BET}, and total pore volume of 682, 1455, 1319 m{sup 2}/g and 0,343, 1,045 and 0.735 cm{sup 3}/g, for the carbon prepared at 450, 550 and 650 °C, respectively. Scanning electron microscopy exhibits a highly developed porosity which is in good agreement with the porous texture derived from gas adsorption data and these results confirm that the activated carbon is dominated by network of slit-shaped mesopores morphology and in some cases by varied micropores morphologies.

[Degradation of Acid Orange 7 with Persulfate Activated by Silver Loaded Granular Activated Carbon].

Science.gov (United States)

Wang, Zhong-ming; Huang, Tian-yin; Chen, Jia-bin; Li, Wen-wei; Zhang, Li-ming

2015-11-01

Granular activated carbon with silver loaded as activator (Ag/GAC) was prepared using impregnation method. N2 adsorption, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) were adopted to characterize the Ag/GAC, showing that silver was successfully loaded on granular activated carbon. The oxidation degradation of acid orange 7 (AO7) by the Ag/GAC activated by persulfate (PS) was investigated at ambient temperature. The influences of factors such as Ag loading, PS or Ag/GAC dosages and initial pH on the degradation of AO7 were evaluated. The results demonstrated that the degradation rate of AO7 could reach more than 95.0% after 180 min when the Ag loading content, PS/AO7 molar ratio, the Ag/GAC dosage were 12.7 mg x g(-1), 120: 1, 1.0 g x L(-1), respectively. The initial pH had significant effect on the AO7 degradation, with pH 5.0 as the optimal pH for the degradation of AO7. The possible degradation pathway was proposed for the AO7 degradation by using UV-visible spectroscopy and gas chromatography-mass spectrometry (GG/MS). The azo bond and naphthalene ring in the AO7 were destroyed during the degradation, with phthalic acid and acetophenone as the main degradation products.

Removal of arsenic and methylene blue from water by granular activated carbon media impregnated with zirconium dioxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Sandoval, Robert; Cooper, Anne Marie; Aymar, Kathryn; Jain, Arti [Environmental Technology, College of Technology and Innovation, Arizona State University, 6073 S. Backus Mall, Mesa, AZ 85212 (United States); Hristovski, Kiril, E-mail: Kiril.Hristovski@asu.edu [Environmental Technology, College of Technology and Innovation, Arizona State University, 6073 S. Backus Mall, Mesa, AZ 85212 (United States)

2011-10-15

Highlights: {yields} The morphology, content and distribution of ZrO{sub 2} nanoparticles inside the pores of GAC are affected by the type of GAC. {yields} Lignite ZrO{sub 2}-GAC exhibited Zr content of 12%, while bituminous based ZrO{sub 2}-GAC exhibited Zr content of 9.5%. {yields} The max. adsorption capacities under equilibrium conditions in 5 mM NaHCO{sub 3} buffered water matrix were {approx}8.6 As/g Zr and {approx}12.2 mg As/g Zr at pH = 7.6. {yields} The max. adsorption capacities under equilibrium conditions in NSF 53 Challenge water matrix while {approx}1.5 mg As/g Zr and {approx}3.2 mg As/g Zr at pH = 7.6. {yields} Introduction of nanoparticles did not impact the MB adsorption capacity of the lignite ZrO{sub 2}-GAC, while the one of bituminous ZrO{sub 2}-GAC decreased. - Abstract: This study investigated the effects of in situ ZrO{sub 2} nanoparticle formation on properties of granulated activated carbon (GAC) and their impacts on arsenic and organic co-contaminant removal. Bituminous and lignite based zirconium dioxide impregnated GAC (Zr-GAC) media were fabricated by hydrolysis of zirconium salt followed by annealing of the product at 400 {sup o}C in an inert environment. Media characterization suggested that GAC type does not affect the crystalline structure of the resulting ZrO{sub 2} nanoparticles, but does affect zirconium content of the media, nanoparticle morphology, nanoparticle distribution, and surface area of Zr-GAC. The arsenic removal performance of both media was compared using 5 mM NaHCO{sub 3} buffered ultrapure water and model groundwater containing competing ions, both with an initial arsenic C{sub 0} {approx} 120 {mu}g/L. Experimental outcomes suggested favorable adsorption energies and higher or similar adsorption capacities than commercially available or experimental adsorbents when compared on the basis of metal content. Short bed adsorber column tests showed that arsenic adsorption capacity decreases as a result of kinetics of

Spanish Broom (Spartium junceum L.) fibers impregnated with vancomycin-loaded chitosan nanoparticles as new antibacterial wound dressing: Preparation, characterization and antibacterial activity.

Science.gov (United States)

Cerchiara, Teresa; Abruzzo, Angela; Ñahui Palomino, Rogers Alberto; Vitali, Beatrice; De Rose, Renata; Chidichimo, Giuseppe; Ceseracciu, Luca; Athanassiou, Athanassia; Saladini, Bruno; Dalena, Francesco; Bigucci, Federica; Luppi, Barbara

2017-03-01

In this work, we propose as new wound dressing, the Spanish Broom fibers impregnated with vancomycin (VM) loaded chitosan nanoparticles. Spanish Broom fibers were extracted by patented method DiCoDe and the morphological, physical and mechanical properties were investigated. Chitosan nanoparticles were prepared by ionic gelation using different weight ratios between chitosan (CH) and tripolyphosphate (TPP). Nanoparticles were characterized in terms of size, zeta potential, yield, encapsulation efficiency, stability and drug release. Finally, the antibacterial activity against Staphylococcus aureus as well as in vitro cytotoxicity on HaCaT cells were evaluated. The best formulation CH/TPP 4:1 was selected based on the encapsulation efficiency and yield. Spanish Broom fibers impregnated with loaded nanoparticles showed an increased antibacterial activity against S. aureus compared to the same fibers containing VM without nanoparticles. Moreover, these fibers were not toxic to HaCaT keratinocytes cells. In conclusion, Spanish Broom fibers impregnated with VM loaded CH/TPP nanoparticles would appear to be a promising candidate for wound dressing application. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis and characterization of Ag nanoparticles decorated mesoporous sintered activated carbon with antibacterial and adsorptive properties

Energy Technology Data Exchange (ETDEWEB)

Wang, Wenxia; Xiao, Kaijun, E-mail: fekjxiao@scut.edu.cn; He, Tinglin; Zhu, Liang, E-mail: zhuliang@scut.edu.cn

2015-10-25

In this study, the sliver nanoparticles (AgNPs) immobilized on the sintered activated carbon (Ag/SAC) were synthesized by the ultrasonic-assisted impregnation method and were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and nitrogen adsorption. SEM showed that the AgNPs were well embedded in the SAC and immersion time had an important influence on final morphologies of AgNPs. Longer immersing duration caused significant aggregation of the AgNPs. The XRD data revealed that the successful synthesis of AgNPs on the SAC and immobilizing AgNPs on sintered active carbon did not change the crystalline degree of SAC. Texture characteristics were determined by analysis of the N{sub 2}/77 K isotherms. The minimum inhibitory concentration (MIC) of Ag/SAC against Escherichia coli (DH5α) and Staphyloccocus aureus (ATCC 29213) was evaluated by a broth dilution method. MICs such as 5 mg/L (against E. coli) and 10 mg/L (against S. aureus) suggest that Ag/SAC have predominant antibacterial activity compared to active carbon. - Highlights: • Sintered active carbon (SAC) was coated with Ag via a facile approach. • The Ag/SAC exhibit good adsorption properties and excellent antibacterial effects. • The Ag/SAC was durable and stable in the application of water purification.

Preparation of High Surface Area Activated Carbon from Spent Phenolic Resin by Microwave Heating and KOH Activation

Science.gov (United States)

Cheng, Song; Zhang, Libo; Zhang, Shengzhou; Xia, Hongying; Peng, Jinhui

2018-01-01

The spent phenolic resin is as raw material for preparing high surface area activated carbon (HSAAC) by microwave-assisted KOH activation. The effects of microwave power, activation duration and impregnation ratio (IR) on the iodine adsorption capability and yield of HSAAC were investigated. The surface characteristics of HSAAC were characterized by nitrogen adsorption isotherms, FTIR, SEM and TEM. The operating variables were optimized utilizing the response surface methodology (RSM) and were identified to be microwave power of 700 W, activation duration of 15 min and IR of 4, corresponding to a yield of 51.25 % and an iodine number of 2,384 mg/g. The pore structure parameters of the HSAAC, i. e., Brunauer-Emmett-Teller (BET) surface area, total pore volume, and average pore diameter were estimated to be 4,269 m2/g, 2.396 ml/g and 2.25 nm, respectively, under optimum conditions. The findings strongly support the feasibility of microwave-assisted KOH activation for preparation of HSAAC from spent phenolic resin.

Dehalogenation of Polybrominated Diphenyl Ethers and Polychlorinated Biphenyl by Bimetallic, Impregnated, and Nanoscale Zerovalent Iron

Science.gov (United States)

Zhuang, Yuan; Ahn, Sungwoo; Seyfferth, Angelia L.; Masue-Slowey, Yoko; Fendorf, Scott; Luthy, Richard G.

2011-01-01

Nanoscale zerovalent iron particles (nZVI), bimetallic nanoparticles (nZVI/Pd), and nZVI/Pd impregnated activated carbon (nZVI/Pd-AC) composite particles were synthesized and investigated for their effectiveness to remove polybrominated diphenyl ethers (PBDEs) and/or polychlorinated biphenyls (PCBs). Palladization of nZVI promoted the dehalogenation kinetics for mono- to tri-BDEs and 2,3,4-trichlorobiphenyl (PCB 21). Compared to nZVI, the iron-normalized rate constants for nZVI/Pd were about 2-, 3-, and 4-orders of magnitude greater for tri-, di-, and mono-BDEs, respectively, with diphenyl ether as a main reaction product. The reaction kinetics and pathways suggest an H-atom transfer mechanism. The reaction pathways with nZVI/Pd favor preferential removal of para-halogens on PBDEs and PCBs. X-ray fluorescence mapping of nZVI/Pd-AC showed that Pd mainly deposits on the outer part of particles, while Fe was present throughout the activated carbon particles. While BDE 21 was sorbed onto activated carbon composites quickly, debromination was slower compared to reaction with freely dispersed nZVI/Pd. Our XPS and chemical data suggest about 7% of the total iron within the activated carbon was zero-valent, which shows the difficulty with in-situ synthesis of a significant fraction of zero-valent iron in the micro-porous material. Related factors that likely hinder the reaction with nZVI/Pd-AC are the heterogenous distribution of nZVI and Pd on activated carbon and/or immobilization of hydrophobic organic contaminants at the adsorption sites thereby inhibiting contact with nZVI. PMID:21557574

Activity of Cu-activated carbon fiber catalyst in wet oxidation of ammonia solution

Energy Technology Data Exchange (ETDEWEB)

Hung, Chang-Mao, E-mail: hungcm1031@gmail.com [Department of Industry Engineering and Management, Yung-Ta Institute of Technology and Commerce, 316 Chung-shan Road, Linlo, Pingtung 909, Taiwan (China)

2009-07-30

Aqueous solutions of 200-1000 mg/L of ammonia were oxidized in a trickle-bed reactor using Cu-activated carbon fiber (ACF) catalysts, which were prepared by incipient wet impregnation with aqueous solutions of copper nitrate that was deposited on ACF substrates. The results reveal that the conversion of ammonia by wet oxidation in the presence of Cu-ACF catalysts was a function of the metal loading weight ratio of the catalyst. The total conversion efficiency of ammonia was 95% during wet oxidation over the catalyst at 463 K at an oxygen partial pressure of 3.0 MPa. Moreover, the effect of the initial concentration of ammonia and the reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid space velocity of less than 3.0 h{sup -1}.

An in vitro Method for Predicting Inhalation Toxicity of Impregnation Spray Products

DEFF Research Database (Denmark)

Sørli, Jorid B.; Hansen, Jitka S.; Nørgaard, Asger Wisti

2015-01-01

Impregnation spray products are used for making surfaces water and dirt repellent. The products are composed of one or more active film-forming components dissolved or suspended in an appropriate solvent mixture. Exposure to impregnation spray products may cause respiratory distress and new cases...

Ionic liquid-impregnated activated carbon for biohydrogen purification in an adsorption unit

Science.gov (United States)

Yusuf, N. Y.; Masdar, M. S.; Isahak, W. N. R. W.; Nordin, D.; Husaini, T.; Majlan, E. H.; Rejab, S. A. M.; Chew, C. L.

2017-06-01

Biological methods for hydrogen production (biohydrogen) are known as energy intensive and can be operated at ambient temperature and pressure; however, consecutive productions such as purification and separation processes still remain challenging in the industry. Various techniques are used to purify and separate hydrogen. These techniques include the use of sorbents/solvents, membranes and cryogenic distillation. In this study, carbon dioxide (CO2) was purified and separated from biohydrogen to produce high purity hydrogen gas. CO2 capture was studied using the activated carbon (AC) modified with the ionic liquid (IL) choline chloride as adsorbent. The physical and chemical properties of the adsorbents were characterized through XRD, FTIR, SEM-EDX, TGA, and BET analyses. The effects of IL loading, flow rate, temperature, and gas mixture were also investigated based on the absorption and desorption of CO2. The CO2 level in the biohydrogen composition was analyzed using a CO2 gas analyzer. The SEM image indicated that the IL homogeneously covered the AC surface. High IL dispersion inlet enhanced the capability of the adsorbent to capture CO2 gas. The thermal stability and presence of the functionalized group of ILs on AC were analyzed by TGA and FTIR techniques, respectively. CO2 adsorption experiments were conducted using a 1 L adsorber unit. Hence, adsorption technologies exhibit potential for biohydrogen purification and mainly affected by adsorbent ability and operating parameters. This research presents an improved biohydrogen technique based on adsorption technology with novel adsorbents. Two different types of commercial CO2 adsorbents were used in the experiment. Results show that the IL/AC exhibited properties suitable for CO2 adsorption. The IL/AC sample presented a high CO2 uptake of 30 wt. % IL when treated at 30 °C for 6 h under a flow rate of 1 L/min. The presence of IL increased the selectivity of CO2 removal during the adsorption process. This IL

Preparation of oil palm empty fruit bunch-based activated carbon for removal of 2,4,6-trichlorophenol: Optimization using response surface methodology

International Nuclear Information System (INIS)

Hameed, B.H.; Tan, I.A.W.; Ahmad, A.L.

2009-01-01

The effects of three preparation variables: CO 2 activation temperature, CO 2 activation time and KOH:char impregnation ratio (IR) on the 2,4,6-trichlorophenol (2,4,6-TCP) uptake and carbon yield of the activated carbon prepared from oil palm empty fruit bunch (EFB) were investigated. Based on the central composite design, two quadratic models were developed to correlate the three preparation variables to the two responses. The activated carbon preparation conditions were optimized using response surface methodology by maximizing both the 2,4,6-TCP uptake and activated carbon yield within the ranges studied. The optimum conditions for preparing activated carbon from EFB for adsorption of 2,4,6-TCP were found as follows: CO 2 activation temperature of 814 deg. C, CO 2 activation time of 1.9 h and IR of 2.8, which resulted in 168.89 mg/g of 2,4,6-TCP uptake and 17.96% of activated carbon yield. The experimental results obtained agreed satisfactorily with the model predictions. The activated carbon prepared under optimum conditions was mesoporous with BET surface area of 1141 m 2 /g, total pore volume of 0.6 cm 3 /g and average pore diameter of 2.5 nm. The surface morphology and functional groups of the activated carbon were respectively determined from the scanning electron microscopy and Fourier transform infrared analysis.

Experimental Study of Impregnation Birch and Aspen Samples

Directory of Open Access Journals (Sweden)

Igor Vladislavovich Grigorev

2014-10-01

Full Text Available An experimental study of wood impregnation was implemented by applying centrifugal methods. The impregnants were a 10% aqueous solution of potassium chloride and a 2% aqueous solution of borax. Birch (Betula pendula and aspen (Populus tremula wood samples in different moisture content were tested. The impregnation time in the centrifugal device were 30 seconds repeated 21 times, and the samples were measured after every 30 seconds. The experimental results were fitted to a nonlinear filtration law, which indicated that the centrifugal wood impregnation was dependent on wood species, wood moisture, rotational speed, and radius. Determination of rotational speed and centrifuge radius for impregnating aspen and birch at varying lengths and humidity under conditions of the nonlinear impregnant filtration law can be done using the example charts that were developed and presented in this study.

Some properties of castor oil affecting its performance as a capacitor impregnant and their significance to future impregnant research

International Nuclear Information System (INIS)

Boicourt, G.P.

1975-01-01

For a considerable time castor oil and polychlorinated biphenyl (PCB) have been the principal impregnants used in energy-storage capacitors. Castor oil has proven to be better than PCB for pulsed applications. PCB's have come under attack as an environmental hazard, while castor oil is a vegetable product and its supply and quality are subject to fluctuation. These two facts make the development of new impregnants desirable. The properties of PCB as a capacitor impregnant are well known. This paper first compares a number of properties of castor oil and PCB's. A comparison is made between the lives of castor oil capacitors and comparable PCB energy-storage capacitors. Some of the physical and chemical properties of castor oil which make it a good pulse capacitor impregnant are examined. These properties can be used as a guide for future research on new pulse capacitor impregnants

Application of Activated Carbon for Removal of Arsenic Ions from Aqueous Solutions

Directory of Open Access Journals (Sweden)

R. Ansari

2007-01-01

Full Text Available The activated carbon (AC was used for removal of As(III and As(V ions from aqueous solutions. Sorption experiments were conducted using both batch and column systems. The effect of some important parameters on sorption of these by AC was studied. It was found that among the different factors affecting sorption capacity and efficiency in removal of arsenic from aqueous solutions, the effect of pH and the oxidation state were the most prominent. The optimum pH values for removal of As(III and As(V from aqueous solutions using AC was found 12 and 3 respectively. Impregnation of AC with sulphur contain organic dyes, it is possible to improve As(III uptake considerably.

In-situ evaluation of the degradable carbon influence for industrial waste water treatment

Energy Technology Data Exchange (ETDEWEB)

Fayomi, O. S. I., E-mail: ojo.fayomi@covenantuniversity.edu.ng, E-mail: fayomio@tut.ac.za, E-mail: ojosundayfayomi3@gmail.com [Department of Mechanical Engineering, Covenant University, Ota, Ogun State (Nigeria); Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, P.M.B. X680, Pretoria (South Africa); Olukanni, D. O. [Department of Civil Engineering, Covenant University, P.M.B. 1023, Ota, Ogun State (Nigeria); Fayomi, G. U. [Department of Environmental Management, Centre for Environmental and Science Education, Lagos State University, Ojo, Lagos State (Nigeria); Joseph, O. O. [Department of Mechanical Engineering, Covenant University, Ota, Ogun State (Nigeria); Popoola, A. P. I. [Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, P.M.B. X680, Pretoria (South Africa)

2016-07-25

A photochemical investigation and synergetic blend for wastewater purification was carried out. Blends of different peels: Potato-, Apple and Pineapples-peals (PAP-peals) were impregnated with aqueous solutions of ZnCl{sub 2} following the variant of the incipient wetness method for activation of activated carbon (AC). Different concentrations were used to produce impregnation ratios. Activation was carried out in a tube furnace by heating to 700°C with 1 hour soaking time. Scanning Electron Microscopic with attached energy dispersive spectrometer (SEM/EDS), Atomic Adsorption Spectrometry (AAS) and Fourier Transform Infrared spectrometer (FTIS) equipments were used for the characterization of the AC produced. The result shows that PAP-peals derived activated carbons had micro porous characteristics. The study revealed that these new combined adsorbents materials are inexpensive, easily available and they have applications for the removal of Cu, Pb and Cr contained in industrial effluents.

Study of adsorption properties of impregnated charcoal for airborne iodine and methyl iodide

International Nuclear Information System (INIS)

Qi-dong, L.; Sui-yuang, H.

1985-01-01

The adsorption characteristics of airborne radioiodine and methyl iodide on impregnated charcoal were investigated. The activated charcoal tested was made from home-made oil-palm shells, and KI and TEDA were used as impregnants. A new technique was used to plot the dynamic partial adsorption isotherm at challenge concentrations (concentration range of iodine: 1-20 ppm v/v). Some adsorption properties of the impregnated charcoal were estimated with the dynamic partial adsorption isotherm. The dependences of the adsorption capacity and penetration behavior for airborne iodine and methyl iodide on the ambient conditions (temperature, relative humidity, and superficial velocity) were studied

Magnetic Fe{sub 2}MO{sub 4} (M:Fe, Mn) activated carbons: Fabrication, characterization and heterogeneous Fenton oxidation of methyl orange

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Thi Dung [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); Phan, Ngoc Hoa [Department of Chemical Technology, Hochiminh University of Technology, 268 Ly Thuong Kiet, District 10, Ho Chi Minh (Viet Nam); Do, Manh Huy, E-mail: huydoma@vast-hcm.ac.vn [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); Ngo, Kim Tham [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); College of science, Can Tho University, 3/2, Can Tho (Viet Nam)

2011-01-30

We present a simple and efficient method for the fabrication of magnetic Fe{sub 2}MO{sub 4} (M:Fe and Mn) activated carbons (Fe{sub 2}MO{sub 4}/AC-H, M:Fe and Mn) by impregnating the activated carbon with simultaneous magnetic precursor and carbon modifying agent followed by calcination. The obtained samples were characterized by nitrogen adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), and the catalytic activity in heterogeneous Fenton oxidation of methyl orange (MO) was evaluated. The resulting Fe{sub 2}MnO{sub 4}/AC-H showed higher catalytic activity in the methyl orange oxidation than Fe{sub 3}O{sub 4}/AC-H. The effect of operational parameters (pH, catalyst loading H{sub 2}O{sub 2} dosage and initial MO concentration) on degradation performance of the oxidation process was investigated. Stability and reusability of selected catalyst were also tested.

Highly regenerable carbon-Fe{sub 3}O{sub 4} core–satellite nanospheres as oxygen reduction electrocatalyst and magnetic adsorbent

Energy Technology Data Exchange (ETDEWEB)

Zhou, Wenqiang [Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, School of Materials Science and Engineering, and Institute for Advanced Study, Tongji University, Shanghai 201804 (China); School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Liu, Minmin; Cai, Chao [Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, School of Materials Science and Engineering, and Institute for Advanced Study, Tongji University, Shanghai 201804 (China); Zhou, Haijun, E-mail: zhouhaijun@just.edu.cn [School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Liu, Rui, E-mail: ruiliu@tongji.edu.cn [Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, School of Materials Science and Engineering, and Institute for Advanced Study, Tongji University, Shanghai 201804 (China)

2017-02-15

We present the synthesis and multifunctional utilization of core-satellite carbon-Fe{sub 3}O{sub 4} nanoparticles to serve as the enabling platform for a range of applications including oxygen reduction reaction (ORR) and magnetic adsorbent. Starting from polydopamine (PDA) nanoparticles and Fe(NO{sub 3}){sub 3}, carbon-Fe{sub 3}O{sub 4} core–satellite nanospheres are synthesized through successive steps of impregnation, ammoniation and carbonization. The synergistic combination of Fe{sub 3}O{sub 4} and N-doped carbon endows the nanocomposite with high electrochemical activity in ORR and mainly four electrons transferred in reaction process. Furthermore, carbon-Fe{sub 3}O{sub 4} nanoparticles used as magnetic adsorbent exhibit the efficient removal of Rhodamine B from an aqueous solution. The recovery and reuse of the adsorbent is demonstrated 5 times without any detectible loss in activity. - Graphical abstract: Starting from polydopamine (PDA) nanoparticles and Fe(NO{sub 3}){sub 3}, carbon-Fe{sub 3}O{sub 4} core–satellite nanospheres are synthesized through successive steps of impregnation, ammoniation and carbonization. The nanocomposites serve as the enabling platform for a range of applications including oxygen reduction reaction (ORR) and magnetic adsorbent. - Highlights: • Carbon-Fe{sub 3}O{sub 4} core–satellite nanospheres are synthesized through successive steps of impregnation, ammoniation and carbonization. • Polydopamine and Fe(NO{sub 3}){sub 3} are precursors for N-doped carbon source and Fe{sub 3}O{sub 4} nanoparticles, respectively. • The nanocomposites exhibit high electrochemical activity in ORR. • The nanocomposites effectively adsorb organic dyes with magnetic recovery and good recycle property.

The influence of Mn species on the SO2 removal of Mn-based activated carbon catalysts

International Nuclear Information System (INIS)

Qu, Yi-Fan; Guo, Jia-Xiu; Chu, Ying-Hao; Sun, Ming-Chao; Yin, Hua-Qiang

2013-01-01

Using Mn(NO 3 ) 2 as precursor, a series of Mn-based activated carbon catalysts were prepared by ultrasound-assisted excessive impregnation method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The influences of Mn species and nitric acid pretreatment on the removal role of SO 2 were investigated. MnO and Mn 3 O 4 coexist in catalysts calcined at 650 and 800 °C and exhibit best SO 2 removal ability, whereas Mn 2 O 3 formed in the catalyst calcined at 500 °C and shows poor activity. After treatment by nitric acid, the C=O of activated carbon support increases and the crystal size of MnO decreases, resulting in the enhancement of the catalytic activity. During reaction process, manganese oxides are gradually transferred into MnO 2 . And this change directly results in a decrease of activity. But the SO 2 removal rate has been maintained in the range of 30–40%, indicating that MnO 2 still has a certain SO 2 removal ability.

Removals of aqueous sulfur dioxide and hydrogen sulfide using CeO2-NiAl-LDHs coating activated carbon and its mix with carbon nano-tubes

KAUST Repository

Li, Jing; Chen, Fangping; Jin, Guanping; Feng, Xiaoshuang; Li, Xiaoxuan

2015-01-01

Ce-doped NiAl/layered double hydroxide was coated at activated carbon by urea hydrolysis method (CeO2-NiAl-LDHs/AC) in one pot, which was characterized by X-ray diffraction, infrared spectra, field emission scanning electron microscope and electrochemical techniques. CeO2-NiAl-LDHs/AC shows good uptake for aqueous sulfur dioxide (483.09mg/g) and hydrogen sulfide (181.15mg/g), respectively at 25°C. Meanwhile, the electrochemical removals of aqueous sulfur dioxide and hydrogen sulfide were respectively investigated at the mix of CeO2-NiAl-LDHs/AC and carbon nano-tubes modified homed paraffin-impregnated electrode. Both sulfur dioxide and hydrogen sulfide could be effectively oxidized to sulfuric acid at 1.0V in alkaline aqueous solution. © 2015 Elsevier B.V.

Removals of aqueous sulfur dioxide and hydrogen sulfide using CeO2-NiAl-LDHs coating activated carbon and its mix with carbon nano-tubes

KAUST Repository

Li, Jing

2015-07-01

Ce-doped NiAl/layered double hydroxide was coated at activated carbon by urea hydrolysis method (CeO2-NiAl-LDHs/AC) in one pot, which was characterized by X-ray diffraction, infrared spectra, field emission scanning electron microscope and electrochemical techniques. CeO2-NiAl-LDHs/AC shows good uptake for aqueous sulfur dioxide (483.09mg/g) and hydrogen sulfide (181.15mg/g), respectively at 25°C. Meanwhile, the electrochemical removals of aqueous sulfur dioxide and hydrogen sulfide were respectively investigated at the mix of CeO2-NiAl-LDHs/AC and carbon nano-tubes modified homed paraffin-impregnated electrode. Both sulfur dioxide and hydrogen sulfide could be effectively oxidized to sulfuric acid at 1.0V in alkaline aqueous solution. © 2015 Elsevier B.V.

Co-adsorption of Trichloroethylene and Arsenate by Iron-Impregnated Granular Activated Carbon.

Science.gov (United States)

Deng, Baolin; Kim, Eun-Sik

2016-05-01

Co-adsorption of trichloroethylene (TCE) and arsenate [As(V)] was investigated using modified granular activated carbons (GAC): untreated, sodium hypochlorite-treated (NaClO-GAC), and NaClO with iron-treated GAC (NaClO/Fe-GAC). Batch experiments of single- [TCE or As(V)] and binary- [TCE and As(V)] components solutions are evaluated through Langmuir and Freundlich isotherm models and adsorption kinetic tests. In the single-component system, the adsorption capacity of As(V) was increased by the NaClO-GAC and the NaClO/Fe-GAC. The untreated GAC showed a low adsorption capacity for As(V). Adsorption of TCE by the NaClO/Fe-GAC was maximized, with an increased Freundlich constant. Removal of TCE in the binary-component system was decreased 15% by the untreated GAC, and NaClO- and NaClO/Fe-GAC showed similar efficiency to the single-component system because of the different chemical status of the GAC surfaces. Results of the adsorption isotherms of As(V) in the binary-component system were similar to adsorption isotherms of the single-component system. The adsorption affinities of single- and binary-component systems corresponded with electron transfer, competitive adsorption, and physicochemical properties.

Kinetic modeling of the purging of activated carbon after short term methyl iodide loading

International Nuclear Information System (INIS)

Friedrich, V.; Lux, I.

1991-01-01

A bimolecular reaction model containing the physico-chemical parameters of the adsorption and desorption was developed earlier to describe the kinetics of methyl iodide retention by activated carbon adsorber. Both theoretical model and experimental investigations postulated constant upstream methyl iodide concentration till the maximum break-through. The work reported here includes the extension of the theoretical model to the general case when the concentration of the challenging gas may change in time. The effect of short term loading followed by purging with air, and an impulse-like increase in upstream gas concentration has been simulated. The case of short term loading and subsequent purging has been experimentally studied to validate the model. The investigations were carried out on non-impregnated activated carbon. A 4 cm deep carbon bed had been challenged by methyl iodide for 30, 90, 120 and 180 min and then purged with air, downstream methyl iodide concentration had been measured continuously. The main characteristics of the observed downstream concentration curves (time and slope of break-through, time and amplitude of maximum values) showed acceptable agreement with those predicted by the model

Functionalized polymer-based spherical activated carbon for liquid and gas phase applications; Funktionalisierte polymerbasierte sphaerische Aktivkohle fuer Fluessig- und Gasphasenanwendungen

Energy Technology Data Exchange (ETDEWEB)

Schrage, Christian; Modrow, Antje; Fichtner, Sven; Giebelhausen, Jann Michael [Bluecher GmbH, Premnitz (Germany); Boehringer, Bertram [Bluecher GmbH, Erkrath (Germany)

2014-02-15

Polymer-based spherical activated carbon (PBSAC) can be functionalized through the integration of reactive compounds. This offers new fields of applications for this adsorbent material. Impregnated PBSAC can be used as broadband sorbent material for respiratory protection, and for removal of certain metals from water, while the integration of nitrogen leads to a material suitable for the clean-up of gases. Functionalization through oxidation or integration of nitrogen atoms enables the concentration of valuable resources like uranium or gold.

Determination of SO2 in the atmosphere using radioactive iodine kryptonate as impregnation medium of chromatographic paper

International Nuclear Information System (INIS)

Pruzinec, J.

1975-01-01

Chromatographic paper was impregnated with radioiodine kryptonate using the macrodiffusion technique. The decrease with time of the activity of the kryptonate-impregnated paper exposed to SO 2 -contaminated air was measured. From the decrease in chromatographic paper activity, the concentration of SO 2 was determined in the range 300 to 700 ppm. (A.K.)

Methods for the characterization of impregnating pitches

Energy Technology Data Exchange (ETDEWEB)

Compin, S.; Ben Aim, R.; Couderc, P.; Saint-Romain, J.L.

1987-11-01

This paper discusses modification of the impregnation performance of various pitches. The filtration ability, which expresses the impregnation performance, was studied using gel permeation chromatography and scanning electron microscopy. 16 refs., 5 figs., 2 tabs.

Carbon-Supported Iron Oxide Particles

DEFF Research Database (Denmark)

Meaz, T.; Mørup, Steen; Koch, C. Bender

1996-01-01

A carbon black ws impregnated with 6 wt% iron using an aqueous solution of iron nitrate. The impregnated carbon was initially dried at 125 C. The effect of heating of the iron oxide phase was investigated at temperatures between 200 and 600 C using Mossbauer spectroscopy. All heat treatments were...... done in an oxygen-containing atmosphere. Ferrihydrite is formed and is stable at and below a temperature of 300 C. At 600 C small particles of maghemite is the dominant iron oxide. A transformation reaction is suggested....

HDO of guaiacol over NiMo catalyst supported on activated carbon derived from castor de-oiled cake

Directory of Open Access Journals (Sweden)

Viviana Ospina

2015-05-01

Full Text Available Physical and chemical activation methods were used to prepare two different activated carbons (ACs from castor de-oiled cake. H2O/CO2 mixture was used as the physical activating agent, and for chemical activation potassium carbonate (K2CO3 was used. For both materials, textural and chemical properties were characterized by N2 adsorption–desorption isotherms, thermogravimetric analysis (TGA, Fourier Transform Infrared Spectroscopy (FTIR, thermal programmed reduction (TPR, X-ray fluorescence (XRF, and scanning electron microscopy (SEM. The ACs were used as supports for NiMo sulfide catalysts, which were prepared by wetness impregnation and in-situ sulfided for the hydrodeoxygenation (HDO of guaiacol (GUA as a model compound of bio-oil. The HDO reaction was carried out in a typical batch reactor at 5 MPa of H2 and 350 °C. Under the same test conditions, commercial catalysts were also tested in the reaction. Although the commercial catalysts displayed higher GUA conversion, the prepared catalysts showed higher activity and non-oxygenated and saturated products yield.

Liquid Phase Plasma Synthesis of Iron Oxide Nanoparticles on Nitrogen-Doped Activated Carbon Resulting in Nanocomposite for Supercapacitor Applications.

Science.gov (United States)

Lee, Heon; Lee, Won-June; Park, Young-Kwon; Ki, Seo Jin; Kim, Byung-Joo; Jung, Sang-Chul

2018-03-25

Iron oxide nanoparticles supported on nitrogen-doped activated carbon powder were synthesized using an innovative plasma-in-liquid method, called the liquid phase plasma (LPP) method. Nitrogen-doped carbon (NC) was prepared by a primary LPP reaction using an ammonium chloride reactant solution, and an iron oxide/NC composite (IONCC) was prepared by a secondary LPP reaction using an iron chloride reactant solution. The nitrogen component at 3.77 at. % formed uniformly over the activated carbon (AC) surface after a 1 h LPP reaction. Iron oxide nanoparticles, 40~100 nm in size, were impregnated homogeneously over the NC surface after the LPP reaction, and were identified as Fe₃O₄ by X-ray photoelectron spectroscopy and X-ray diffraction. NC and IONCCs exhibited pseudo-capacitive characteristics, and their specific capacitance and cycling stability were superior to those of bare AC. The nitrogen content on the NC surface increased the compatibility and charge transfer rate, and the composites containing iron oxide exhibited a lower equivalent series resistance.

Removal of Chlorinated Chemicals in H2 Feedstock Using Modified Activated Carbon

Directory of Open Access Journals (Sweden)

Prapaporn Luekittisup

2015-01-01

Full Text Available Activated carbon (GAC was impregnated by sodium and used as adsorbent to remove chlorinated hydrocarbon (CHC gases contaminated in H2 feedstock. The adsorption was carried out in a continuous packed-bed column under the weight hourly space velocity range of 0.8–1.0 hr−1. The adsorption capacity was evaluated via the breakthrough curves. This modified GAC potentially adsorbed HCl and VCM of 0.0681 gHCl/gadsorbent and 0.0026 gVCM/gadsorbent, respectively. It showed higher adsorption capacity than SiO2 and Al2O3 balls for both organic and inorganic CHCs removal. In addition, the kinetic adsorption of chlorinated hydrocarbons on modified GAC fit well with Yoon-Nelson model.

Developing low-cost carbon-based sorbents for Hg capture from flue gas

Energy Technology Data Exchange (ETDEWEB)

Ron Perry; Janos Lakatos; Colin E. Snape; Cheng-gong Sun [University of Nottingham (United Kingdom). UK Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

2005-07-01

To help reduce the cost of Hg capture, a number of low-cost carbons are being investigated, including tyre char, PFA carbons and gasification residues. This contribution reports the breakthrough capacities in fixed-bed screening tests for these materials in relation to those for commercial active carbons, including Norit FGD and the extent to which breakthrough capacities can be improved by MnO{sub 2} impregnation. 7 refs., 3 figs., 1 tab.

Zirconium-carbon hybrid sorbent for removal of fluoride from water: oxalic acid mediated Zr(IV) assembly and adsorption mechanism

Science.gov (United States)

Halla, Velazquez-Jimenez Litza; Hurt Robert, H; Juan, Matos; Rene, Rangel-Mendez Jose

2014-01-01

When activated carbon (AC) is modified with zirconium(IV) by impregnation or precipitation, the fluoride adsorption capacity is typically improved. There is significant potential to improve these hybrid sorbent by controlling the impregnation conditions, which determine the assembly and dispersion of the Zr phases on carbon surfaces. Here, commercial activated carbon was modified with Zr(IV) together with oxalic acid (OA) used to maximize the zirconium dispersion and enhance fluoride adsorption. Adsorption experiments were carried out at pH 7 and 25 °C with a fluoride concentration of 40 mg L−1. The OA/Zr ratio was varied to determine the optimal conditions for subsequent fluoride adsorption. The data was analyzed using the Langmuir and Freundlich isotherm models. FTIR, XPS and the surface charge distribution were performed to elucidate the adsorption mechanism. Potentiometric titrations showed that the modified activated carbon (ZrOx-AC) possesses positive charge at pH lower than 7, and FTIR analysis demonstrated that zirconium ions interact mainly with carboxylic groups on the activated carbon surfaces. Moreover, XPS analysis demonstrated that Zr(IV) interacts with oxalate ions, and the fluoride adsorption mechanism is likely to involve –OH− exchange from zirconyl oxalate complexes. PMID:24359079

Evaluation of the mechanical properties of carbon fiber after electron beam irradiation

International Nuclear Information System (INIS)

Giovedi, Claudia; Diva Brocardo Machado, Luci; Augusto, Marcos; Segura Pino, Eddy; Radino, Patricia

2005-01-01

Carbon fibers are used as reinforcement material in epoxy matrix in advanced composites. An important aspect of the mechanical properties of composites is associated to the adhesion between the surface of the carbon fiber and the epoxy matrix. This paper aimed to the evaluation of the effects of EB irradiation on the tensile properties of two different carbon fibers prepared as resin-impregnated specimens. The fibers were EB irradiated before the preparation of the resin-impregnated specimens for mechanical tests. Observations of the specimens after breakage have shown that EB irradiation promoted significant changes in the failure mode. Furthermore, the tensile strength data obtained for resin-impregnated specimens prepared with carbons fibers previously irradiated presented a slight tendency to be higher than those obtained from non-irradiated carbon fibers

Scavenging remazol brilliant blue R dye using microwave-assisted activated carbon from acacia sawdust: Equilibrium and kinetics studies

Science.gov (United States)

Yusop, M. F. M.; Aziz, H. A.; Ahmad, M. A.

2017-10-01

This work explores the feasibility of microwave-assisted acacia wood based activated carbon (AWAC) for remazol brilliant blue R (RBBR) dye removal from synthetic wastewater. Acacia wood (AW) was impregnated with potassium hydroxide (KOH) and heated using microwave, resulting tremendously high fixed carbon content, surface area, total pore volume and adsorption capacity of 81.14%, 1045.56m2/g, 0.535cm3/g and 263.16mg/g respectively. Batch study conducted divulged an increasing trend in RBBR uptake when initial RBBR concentration and contact time were increased. pH study revealed that RBBR adsorption was best at acidic condition. Langmuir isotherm model fitted well the adsorption equilibrium data while the adsorption kinetic was found to follow the pseudo-second-order kinetic model.

Preparation and characterization of CeO2 highly dispersed on activated carbon

International Nuclear Information System (INIS)

Serrano-Ruiz, J.C.; Ramos-Fernandez, E.V.; Silvestre-Albero, J.; Sepulveda-Escribano, A.; Rodriguez-Reinoso, F.

2008-01-01

A new material constituted by cerium dioxide highly dispersed on activated carbon (CeO 2 /AC) was prepared by an impregnation method using cerium(III) nitrate as CeO 2 precursor. In order to evaluate the degree of ceria dispersion on the carbon support, CeO 2 /AC was characterized by a number of techniques: thermogravimetry coupled with a mass spectrometer (TG-MS), N 2 adsorption at 77 K, temperature-programmed desorption (TPD), temperature-programmed reduction (TPR) and transmission electron microscopy (TEM). The analysis of the decomposition process under inert atmosphere indicated that cerium nitrate decomposes at 440-460 K, with the evolution of NO. Furthermore, this process produces an additional oxidation of the carbon surface (with evolution of N 2 O) and the subsequent onset of new oxygen surface groups, detected by means of temperature-programmed desorption. The ceria deposition process takes place with a decrease in the N 2 adsorption capacity of the starting carbon support, and the analysis of the pore size distribution showed that the majority of ceria particles are situated at the most internal part of the carbon porosity. The temperature-programmed reduction profile of CeO 2 /AC was very different to that shown by unsupported CeO 2 , with only one continuous reduction process at low temperatures (800-900 K). Finally, TEM pictures gave direct evidence that ceria is highly dispersed on the carbon surface, with a narrow CeO 2 particle distribution centred around 3 nm

Carbon Cryogel and Carbon Paper-Based Silicon Composite Anode Materials for Lithium-Ion Batteries

Science.gov (United States)

Woodworth, James; Baldwin, Richard; Bennett, William

2010-01-01

A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 6 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-5 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

Supercritical CO2 impregnation of PLA/PCL films with natural substances for bacterial growth control in food packaging.

Science.gov (United States)

Milovanovic, Stoja; Hollermann, Gesa; Errenst, Cornelia; Pajnik, Jelena; Frerich, Sulamith; Kroll, Stephen; Rezwan, Kurosch; Ivanovic, Jasna

2018-05-01

Biodegradable polymers with antibacterial properties are highly desirable materials for active food packaging applications. Thymol, a dietary monoterpene phenol with a strong antibacterial activity is abundant in plants belonging to the genus Thymus. This study presents two approaches for supercritical CO 2 impregnation of poly(lactic acid)(PLA)/poly(ε-caprolactone)(PCL) blended films to induce antibacterial properties of the material: (i) a batch impregnation process for loading pure thymol, and (ii) an integrated supercritical extraction-impregnation process for isolation of thyme extract and its incorporation into the films, operated in both batch or semi-continuous modes with supercritical solution circulation. The PCL content in films, impregnation time and CO 2 flow regime were varied to maximize loading of the films with thymol or thyme extract with preserving films' structure and thermal stability. Representative film samples impregnated with thymol and thyme extract were tested against Gram (-) (Escherichia coli) and Gram(+) (Bacillus subtilis) model strains, by measuring their metabolic activity and re-cultivation after exposure to the films. The film containing thymol (35.8 wt%) showed a strong antibacterial activity leading to a total reduction of bacterial cell viability. Proposed processes enable fast, controlled and organic solvent-free fabrication of the PLA/PCL films containing natural antibacterial substances at moderately low temperature, with a compact structure and a good thermal stability, for potential use as active food packaging materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electrical capacitance of fibrous carbon composites in supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Babel, Krzysztof [Institute of Chemical Wood Technology, Agricultural Academy in Poznan, ul. Wojska Polskiego 38/42, 60-637 Poznan (Poland); Jurewicz, Krzysztof [Institute of Chemistry and Technical Electrochemistry, Poznan University of Technology, ul. Piotrowo 3, 60-965 Poznan (Poland)

2002-06-20

The aim of this work was the application of active carbon composites as electrode material for supercapacitors. We have produced and investigated composites from viscose cellulose fibers impregnated with novolak and resolic resins. Composition and porous structure of the composites were described and electrochemical properties determined by galvanostatic and potentiodynamic methods. Dependence of electrical capacitance on treatment procedure and some of the structural parameters was confirmed. The use of novolak resin for activation with carbon dioxide was more advantageous. Positive electrode revealed better performance in acidic conditions (185 F/g) while negative electrode in alkaline conditions (160 F/g)

Integrated basic treatment of activated carbon for enhanced CO{sub 2} selectivity

Energy Technology Data Exchange (ETDEWEB)

Adelodun, Adedeji Adebukola; Jo, Young-Min, E-mail: ymjo@khu.ac.kr

2013-12-01

We attempted the use of three chemical agents viz nitric acid (HN), calcium nitrate (CaN) and calcium ethanoate (CaEt) to achieve enhanced CO{sub 2} selective adsorption by activated carbon (AC). In dry phase treatment, microporous coconut shell-based carbon (CS) exhibits higher CO{sub 2} capacity than coal-based. However, upon wet-phase pre-treatment, modified CS samples showed lesser CO{sub 2} adsorption efficiency. Surface characterization with X-ray photoelectron spectroscopy confirms the presence of calcium and amine species on the samples with integrated treatment (A-CaN). These samples recorded the highest low-level CO{sub 2} capture despite calcinated CaEt-doped samples (C-CaEt) showing the highest value for pure and high level CO{sub 2} adsorption capacities. The slope and linearity values of isobaric desorption were used to estimate the proportion of CO{sub 2} chemisorbed and heterogeneity of the adsorbents’ surfaces respectively. Consequently, integrated basic impregnation provides the most efficient adsorbents for selective adsorption of both indoor and outdoor CO{sub 2} levels.

Optimization of microwave-assisted rubberwood sawdust based activated carbon preparation conditions for methylene blue removal

Science.gov (United States)

Khasri, Azduwin; Ahmad, Mohd Azmier

2017-10-01

Optimum preparation conditions of rubberwood sawdust based activated carbon (RSAC) for methylene blue (MB) dye removal was studied. RSAC was produced by applying physiochemical activation method by using potassium hydroxide as a chemical agent which accompanied by carbon dioxide gasification under microwave heating. The effects of microwave power, irradiation time and impregnation ratio on two types of responses namely MB removal and RSAC yield using the center composite design (CCD) were also included in this study. The preparation variables correlation for responses was developed by two quadratic models. Optimum preparation conditions of RSAC were obtained at microwave power, irradiation time and IR of 354 W, 4.5 minutes and 0.98, respectively, which resulted MB removal and yield of 83.79% and 28%, respectively. The average pore diameter, surface area and total pore volume of optimized RSAC were 4.12 nm, 796.33 m2/g and 0.4219 cm3/g, respectively. This sample was found to has well-developed pores on its surface and can be a promising adsorbent for MB removal from aqueous solution.

Environmental impact associated with activated carbon preparation from olive-waste cake via life cycle assessment.

Science.gov (United States)

Hjaila, K; Baccar, R; Sarrà, M; Gasol, C M; Blánquez, P

2013-11-30

The life cycle assessment (LCA) environmental tool was implemented to quantify the potential environmental impacts associated with the activated carbon (AC) production process from olive-waste cakes in Tunisia. On the basis of laboratory investigations for AC preparation, a flowchart was developed and the environmental impacts were determined. The LCA functional unit chosen was the production of 1 kg of AC from by-product olive-waste cakes. The results showed that impregnation using H3PO4 presented the highest environmental impacts for the majority of the indicators tested: acidification potential (62%), eutrophication (96%), ozone depletion potential (44%), human toxicity (64%), fresh water aquatic ecotoxicity (90%) and terrestrial ecotoxicity (92%). One of the highest impacts was found to be the global warming potential (11.096 kg CO2 eq/kg AC), which was equally weighted between the steps involving impregnation, pyrolysis, and drying the washed AC. The cumulative energy demand of the AC production process from the by-product olive-waste cakes was 167.63 MJ contributed by impregnation, pyrolysis, and drying the washed AC steps. The use of phosphoric acid and electricity in the AC production were the main factors responsible for the majority of the impacts. If certain modifications are incorporated into the AC production, such as implementing synthesis gas recovery and reusing it as an energy source and recovery of phosphoric acid after AC washing, additional savings could be realized, and environmental impacts could be minimized. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mesoporous-activated carbon prepared from chitosan flakes via single-step sodium hydroxide activation for the adsorption of methylene blue.

Science.gov (United States)

Marrakchi, F; Ahmed, M J; Khanday, W A; Asif, M; Hameed, B H

2017-05-01

In this work, mesoporous-activated carbon (CSAC) was prepared from chitosan flakes (CS) via single-step sodium hydroxide activation for the adsorption of methylene blue (MB). CSAC was prepared using different impregnation ratios of NaOH:CS (1:1, 2:1, 3:1, and 4:1) at 800°C for 90min. The adsorption performance of CSAC was evaluated for MB at different adsorption variables, such MB initial concentrations (25-400mg/L), solution pH (3-11), and temperature (30-50°C). The adsorption isotherm data of CSAC-MB were well fitted to Langmuir model with a maximum adsorption capacity 143.53mg/g at 50°C. Best representation of kinetic data was obtained by the pseudo-second order model. CSAC exhibited excellent adsorption uptake for MB and can potentially be used for other cationic dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

Silicon Composite Anode Materials for Lithium Ion Batteries Based on Carbon Cryogels and Carbon Paper

Science.gov (United States)

Woodworth, James; Baldwin, Richard; Bennett, William

2010-01-01

A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nanofoams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

Impregnation of leather during "freeze-drying"

DEFF Research Database (Denmark)

Storch, Mikkel; Vestergaard Poulsen Sommer, Dorte; Hovmand, Ida

2016-01-01

Freeze-drying is a recognized method for the preservation of waterlogged objects. Naturally, freeze-drying has also been used for waterlogged archaeological leather often after treatment with Na2.EDTA and impregnation with PEG; but the treated leather sometimes suffers from “excessive drying......” becoming too stiff and brittle. The aim of this study was to examine the effect of a conventional freeze-drying method against an alternative freeze-drying method that preserves the natural moisture content of the leather. Both new and archaeological waterlogged leather were included in the study...... suggest that the process which takes place within the leather during the freeze-drying in not actual freeze-drying, but rather a sophisticated way of distributing the impregnating agent. The pure ice phase freezes out, but the impregnating agent remains liquid as the temperature does not become low enough...

The influence of Mn species on the SO{sub 2} removal of Mn-based activated carbon catalysts

Energy Technology Data Exchange (ETDEWEB)

Qu, Yi-Fan [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Guo, Jia-Xiu, E-mail: guojiaxiu@scu.edu.cn [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065 (China); Chu, Ying-Hao [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065 (China); Sun, Ming-Chao [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Yin, Hua-Qiang, E-mail: hqyin@scu.edu.cn [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065 (China)

2013-10-01

Using Mn(NO{sub 3}){sub 2} as precursor, a series of Mn-based activated carbon catalysts were prepared by ultrasound-assisted excessive impregnation method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The influences of Mn species and nitric acid pretreatment on the removal role of SO{sub 2} were investigated. MnO and Mn{sub 3}O{sub 4} coexist in catalysts calcined at 650 and 800 °C and exhibit best SO{sub 2} removal ability, whereas Mn{sub 2}O{sub 3} formed in the catalyst calcined at 500 °C and shows poor activity. After treatment by nitric acid, the C=O of activated carbon support increases and the crystal size of MnO decreases, resulting in the enhancement of the catalytic activity. During reaction process, manganese oxides are gradually transferred into MnO{sub 2}. And this change directly results in a decrease of activity. But the SO{sub 2} removal rate has been maintained in the range of 30–40%, indicating that MnO{sub 2} still has a certain SO{sub 2} removal ability.

Effects of pore sizes and oxygen-containing functional groups on desulfurization activity of Fe/NAC prepared by ultrasonic-assisted impregnation

International Nuclear Information System (INIS)

Shu, Song; Guo, Jia-Xiu; Liu, Xiao-Li; Wang, Xue-Jiao; Yin, Hua-Qiang; Luo, De-Ming

2016-01-01

Graphical abstract: - Highlights: • Fe/NAC-60 exhibits the best desulfurization activity. • Different oscillation time can change surface area and pore volume of catalysts. • Ultrasonic oscillation increases Fe dispersion on carrier and effective pores. • Pore sizes play a crucial role during the SO 2 removal. - Abstract: A series of Fe-loaded activated carbons treated by HNO 3 (Fe/NAC) were prepared by incipient impregnation method with or without ultrasonic assistance and characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy with energy disperse spectroscope (SEM-EDS), transmission electron microscopy (TEM) and N 2 adsorption/desorption. The desulfurization activities were evaluated at a fixed bed reactor under a mixed gas simulated from flue gas. The results showed that desulfurization activity from excellent to poor is as follows: Fe/NAC-60 > Fe/NAC-80 > Fe/NAC-30 > Fe/NAC-15 > Fe/NAC-0 > Fe/NAC-100 > NAC. Fe/NAC-60 exhibits the best desulfurization activity and has breakthrough sulfur capacity of 319 mg/g and breakthrough time of 540 min. The introduction of ultrasonic oscillation does not change the form of Fe oxides on activated carbon but can change the dispersion and relative contents of Fe 3 O 4 . The types of oxygen-containing functional groups have no obvious change for all samples but the texture properties show some differences when they are oscillated for different times. The fresh Fe/NAC-60 has a surface area of 1045 m 2 /g and total pore volume of 0.961 cm 3 /g with micropore volume of 0.437 cm 3 /g and is larger than Fe/NAC-0 (823 m 2 /g, 0.733 and 0.342 cm 3 /g). After desulfurization, surface area and pore volume of all samples decrease significantly, and those of the exhausted Fe/NAC-60 decrease to 233 m 2 /g and 0.481 cm 3 /g, indicating that some byproducts deposit on surface to cover pores. Pore size distribution influences SO 2 adsorption, and fresh Fe/NAC-60 has

[Adsorption behavior and influence factors of p-nitroaniline on high surface area activated carbons prepared from plant stems].

Science.gov (United States)

Li, Kun-quan; Zheng, Zheng; Luo, Xing-zhang

2010-08-01

Low-cost and high surface area microporous activated carbons were prepared from Spartina alternilora and cotton stalk with KOH activation under the conditions of impregnation ratio of 3.0, activation temperature at 800 degrees C and activation time of 1.5 h. The adsorption behavior of p-nitroaniline on the activated carbons was investigated by batch sorption experiments. The influences of solution pH value, adsorbent dose and temperature were investigated. The adsorption isotherm and thermodynamic characteristics were also discussed. The Spartina alterniflora activated carbon (SA-AC) has a high surface area of 2825 m2 x g(-1) and a micropore volume of 1.192 cm3 x g(-1). The BET surface area and micropore volume of the cotton stalk activated carbon (CS-AC) are 2135 m2 x g(-1) and 1.011 cm3 x g(-1), respectively. The sorption experiments show that both the activated carbons have high sorption capacity for p-nitroaniline. The Langmuir maximum sorption amount was found to be 719 mg x g(-1) for SA-AC and 716 mg x g(-1) for CS-AC, respectively. The sorption was found to depend on solution pH, adsorbent dose, and temperature. The optimum pH for the removal of p-nitroaniline was found to be 7.0. The Freundlich model and Redlich-Peterson model can describe the experimental data effectively. The negative changes in free energy (delta G0) and enthalpy (delta H0) indicate that the sorption is a spontaneous and exothermic procedure. The negative values of the adsorption entropy delta S0 indicate that the mobility of p-nitroaniline on the carbon surface becomes more restricted as compared with that of those in solution.

Wide electrochemical window of supercapacitors from coffee bean-derived phosphorus-rich carbons.

Science.gov (United States)

Huang, Congcong; Sun, Ting; Hulicova-Jurcakova, Denisa

2013-12-01

Phosphorus-rich carbons (PCs) were prepared by phosphoric acid activation of waste coffee grounds in different impregnation ratios. PCs were characterized by nitrogen and carbon dioxide adsorption and X-ray photoelectron spectroscopy. The results indicate that the activation step not only creates a porous structure, but also introduces various phosphorus and oxygen functional groups to the surface of carbons. As evidenced by cyclic voltammetry, galvanostatic charge/discharge, and wide potential window tests, a supercapacitor constructed from PC-2 (impregnation ratio of 2), with the highest phosphorus content, can operate very stably in 1 M H2 SO4 at 1.5 V with only 18 % degradation after 10 000 cycles at a current density of 5 A g(-1) . Due to the wide electrochemical window, a supercapacitor assembled with PC-2 has a high energy density of 15 Wh kg(-1) at a power density of 75 W kg(-1) . The possibility of widening the potential window above the theoretical potential for the decomposition of water is attributed to reversible electrochemical hydrogen storage in narrow micropores and the positive effect of phosphorus-rich functional groups, particularly the polyphosphates on the carbon surface. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Remarkable activity of nitrogen-doped hollow carbon spheres encapsulated Cu on synthesis of dimethyl carbonate: Role of effective nitrogen

Science.gov (United States)

Li, Haixia; Zhao, Jinxian; Shi, Ruina; Hao, Panpan; Liu, Shusen; Li, Zhong; Ren, Jun

2018-04-01

A critical aspect in the improvement of the catalytic performance of Cu-based catalysts for the synthesis of dimethyl carbonate (DMC) is the development of an appropriate support. In this work, nitrogen-doped hollow carbon spheres (NHCSs), with 240 nm average diameter, 17 nm shell thickness, uniform mesoporous structure and a specific surface area of 611 m2 g-1, were prepared via a two-step Stӧber method. By varying the quantity of nitrogen-containing phenols used in the preparation it has been possible to control the nitrogen content and, consequently, the sphericity of the NHCSs. It was found that perfect spheres were obtained for nitrogen contents below 5.4 wt.%. The catalysts (Cu@NHCSs) were prepared by the hydrothermal impregnation method. The catalytic activity towards DMC synthesis was notably enhanced due to the immobilization effect on Cu particles and the enhanced electron transfer effect exercised by the effective nitrogen species, including pyridinic-N and graphitic-N. When the average size of the copper nanoparticles was 7.4 nm and the nitrogen content was 4.0 wt.%, the values of space-time yield of DMC and of turnover frequency (TOF) reached 1528 mg/(g h) and 11.0 h-1, respectively. The TOF value of Cu@NHCSs was 6 times higher than non-doped Cu@Carbon (2.1 h-1). The present work introduces the potential application of nitrogen-doped carbon materials and presents a novel procedure for the preparation of catalysts for DMC synthesis.

Preparation and evaluation of coal-derived activated carbons for removal of mercury vapor from simulated coal combustion flue fases

Science.gov (United States)

Hsi, H.-C.; Chen, S.; Rostam-Abadi, M.; Rood, M.J.; Richardson, C.F.; Carey, T.R.; Chang, R.

1998-01-01

Coal-derived activated carbons (CDACs) were tested for their suitability in removing trace amounts of vapor-phase mercury from simulated flue gases generated by coal combustion. CDACs were prepared in bench-scale and pilot-scale fluidized-bed reactors with a three-step process, including coal preoxidation, carbonization, and then steam activation. CDACs from high-organicsulfur Illinois coals had a greater equilibrium Hg0 adsorption capacity than activated carbons prepared from a low-organic-sulfur Illinois coal. When a low-organic-sulfur CDAC was impregnated with elemental sulfur at 600 ??C, its equilibrium Hg0 adsorption capacity was comparable to the adsorption capacity of the activated carbon prepared from the high-organicsulfur coal. X-ray diffraction and sulfur K-edge X-ray absorption near-edge structure examinations showed that the sulfur in the CDACs was mainly in organic forms. These results suggested that a portion of the inherent organic sulfur in the starting coal, which remained in the CDACs, played an important role in adsorption of Hg0. Besides organic sulfur, the BET surface area and micropore area of the CDACs also influenced Hg0 adsorption capacity. The HgCl2 adsorption capacity was not as dependent on the surface area and concentration of sulfur in the CDACs as was adsorption of Hg0. The properties and mercury adsorption capacities of the CDACs were compared with those obtained for commercial Darco FGD carbon.

Influence of impregnation by inorganic substances on the yield of pyrolysis products

Energy Technology Data Exchange (ETDEWEB)

Shevkoplyas, V N; Saranchuk, V I [AN Ukrainskoj SSR, Donetsk (Ukraine). Inst. Fiziko-Organicheskoj Khimii i Uglekhimii

1998-09-01

In papers was shown that fossil coals impregnation by aqueous solution of inorganic substances with a subsequent pyrolysis leads to the rise of the rate and depth of its organic mass destruction into liquid and gaseous products. This is, apperently, conditioned by changes in coals structure already on the stage of treatment. But, there are few papers that study an activating effect of inorganic reactants upon natural coals structure and their behaviour at pyrolysis. One of the methods which allows to judge structural transformation in coals at their impregnation by inorganic substances is an X-ray analysis. (orig.)

THE INFLUENCE OF Pd IMPREGNATION INTO Al-MCM-41 ON THE CHARACTERS AND ACTIVITY FOR BIOGASOLINE PRODUCTION BY CATALYTIC HYDROCRACKING OF FAMEs FROM NYAMPLUNG SEED OIL (Calophyllum Inophyllum

Directory of Open Access Journals (Sweden)

Hendro Juwono

2013-08-01

Full Text Available Biogasoline have been synthesized through catalytic hydrocracking reaction against FAMEs compounds (fatty acid methyl esters obtained from the transesterification of Nyamplung seed oil. The performance of Al-MCM-41 and Pd/Al-MCM-41 as the catalytic hydrocracking was compared. In this research, the influence of Pd impregnation into Al-MCM-41 catalyst on the characters and catalytic activity has been evaluated. The characters determined were crystallinity by using X-Ray Diffractometer (XRD, Si/Al ratio by Inductively Coupled Plasma (ICP, the acidity by pyridine adsorption, the surface area and pore volume by surface area analyzer and the morphology by Scanning Electron Microscopy (SEM. Catalytic activity was examined for hydrocracking of free fatty acid methyl esters (FAMEs produced from the transesterification of Nyamplung seed oil, by Hydrogen flowing. The research result showed that impregnation of Pd into Al-MCM-41 has been successfully carried out, which did not destroy the structural morphology of the catalyst. It was also discovered that the Pd impregnation could increase Si/Al ratio and the acidity but it leads to decrease in the catalyst surface area and the volume. Furthermore, Pd impregnated Al-MCM-41 showed superior activity compared to Al-MCM-41 for FAMEs hydrocracking. The superiority was indicated by higher effectiveness and yields selectiveness, that were 100% hydrocarbon composed of C9-C18 that was dominated by C12 emerging the gasoline fraction, compared of that by the results used Al-MCM-41 catalyst that were 97% hydrocarbon consisted of C8-C20 with equal abundance.

Fabrication of palladium nanoparticles immobilized on an amine-functionalized ceramic membrane support using a nanoparticulate colloidal impregnation method with enhanced catalytic properties

Energy Technology Data Exchange (ETDEWEB)

Du, Yan; Chen, Rizhi [Nanjing Tech University, Nanjing (China)

2015-09-15

An efficient and reusable catalyst was developed by depositing palladium nanoparticles on an amine-functionalized ceramic membrane support using a nanoparticulate colloidal impregnation method. The as-prepared Pdloaded ceramic membrane support was characterized by XRD, SEM, EDS, TEM, XPS, ICP, and its catalytic properties were investigated in the liquid-phase p-nitrophenol hydrogenation. A comparative study was also made with the palladium nanoparticles deposited on an amine-functionalized ceramic membrane support by an impregnation-reduction method. The palladium nanoparticles could be homogeneously immobilized on the ceramic membrane support surface, and exhibited excellent catalytic performance in the p-nitrophenol hydrogenation. The catalytic activity of the Pdloaded ceramic membrane support prepared by the nanoparticulate colloidal impregnation method increased by 16.6% compared to that of impregnation-reduction method. In the nanoparticulate colloidal impregnation method, palladium nanoparticles were presynthesized, higher loading of Pd(0) could be obtained, resulting in better catalytic activity. The as-prepared Pd-loaded ceramic membrane support could be easily reused for several cycles without appreciable degradation of catalytic activity.

Apple snack enriched with L-arginine using vacuum impregnation/ohmic heating technology.

Science.gov (United States)

Moreno, Jorge; Echeverria, Julian; Silva, Andrea; Escudero, Andrea; Petzold, Guillermo; Mella, Karla; Escudero, Carlos

2017-07-01

Modern life has created a high demand for functional food, and in this context, emerging technologies such as vacuum impregnation and ohmic heating have been applied to generate functional foods. The aim of this research was to enrich the content of the semi-essential amino acid L-arginine in apple cubes using vacuum impregnation, conventional heating, and ohmic heating. Additionally, combined vacuum impregnation/conventional heating and vacuum impregnation/ohmic heating treatments were evaluated. The above treatments were applied at 30, 40 and 50  ℃ and combined with air-drying at 40 ℃ in order to obtain an apple snack rich in L-arginine. Both the impregnation kinetics of L-arginine and sample color were evaluated. The impregnated samples created using vacuum impregnation/ohmic heating at 50 ℃ presented a high content of L-arginine, an effect attributed primarily to electropermeabilization. Overall, vacuum impregnation/ohmic heating treatment at 50 ℃, followed by drying at 40 ℃, was the best process for obtaining an apple snack rich in L-arginine.

A Binder Viscosity Effect on the Wet-Wounded Composite Porosity in the Impregnating Bath

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M. A. Komkov

2014-01-01

Full Text Available The aim of this work is to define experimentally an impregnation rate of VM-1 glass fibers and CBM aramid bundles with the epoxy binder EDB-10 using wet method of winding. During the impregnation process of the fibrous fillers by the liquid binder, air is displaced from the interfiber space of fiber and bundle. With the composite product winding a fiber impregnation process is short. That is why gas inclusions or pores are formed in the polymer-fiber compositeThe impregnation rate or porosity of wound material will depend directly on the binder viscosity. To reduce an epoxy binder viscosity temporarily is possible by two ways. The first is to heat a liquid epoxy composition EDB-10 to the maximum possible temperature during the winding process of the product. The second method is to dilute the binder by a solvent, such as acetone or alcohol. However, the solvent reduces its strength.The paper presents experimental data to show the volumetric content of pores in the wound composite affected only by the viscosity of the epoxy binder. Heating a binder allowed us to regulate a changing conditional viscosity of the binder in the impregnating bath for the normal conditions of impregnation. Other impacts on the impregnation and filament-winding processes, such as filler kinks, squeeze, vacuuming binder, highly tensioned winding, and others were not used.Experimentally obtained dependences of the porosity value of wound composite on the conditional viscosity of binder are nonlinear and can be used to design heaters for impregnating devices of winders. The research technique and results can be used in development of technological processes to manufacture composite structures by winding from the other reinforcing fibrous fillers and thermo-active binders.The results show that the volumetric content of pores can significantly vary within 8 - 14 % of material volume. Therefore, to reduce the number of pores in the wound composite to 1-2 %, auxiliary

Fabrication of nanostructured clay-carbon nanotube hybrid nanofiller by chemical vapour deposition

International Nuclear Information System (INIS)

Manikandan, Dhanagopal; Mangalaraja, Ramalinga Viswanathan; Siddheswaran, Rajendran; Avila, Ricardo E.; Ananthakumar, Solaiappan

2012-01-01

Growth of multiwalled carbon nanotube (CNT) assemblies by chemical vapour decomposition (CVD) technique was achieved through decomposition of acetylene using iron impregnated montmorillonite (MM) catalysts. Various amounts of iron loaded montmorillonite catalysts were prepared by wet impregnation method and calcined at 450 °C. The catalysts were subjected to X-ray diffraction (XRD) and surface area analyses. Acetylene decomposition at a feed ratio of N 2 :H 2 :C 2 H 2 = 1:1:0.18 was conducted in the presence of iron impregnated montmorillonite catalysts in the CVD reactor for the growth of CNT structures. The role of Fe-activated clay catalyst on the formation of CNT structures has been systematically examined at various temperatures and correlated with the morphological features of CNTs. Catalyst assisted acetylene decomposition results the formation of different carbon nanostructures such as nanotubes, nanofibres and nanoflakes. These clay-CNT products were characterised for their morphological, thermal, qualitative and quantitative analyses. The morphological variations of CNT assemblies reveal Fe-montmorillonite catalysts have high selectivity at given reaction conditions. Thermogravimetric and Raman spectral analyses prove that the CNTs contain a good crystallanity and less structural defects.

Fabrication of nanostructured clay-carbon nanotube hybrid nanofiller by chemical vapour deposition

Energy Technology Data Exchange (ETDEWEB)

Manikandan, Dhanagopal, E-mail: dmani_cat@yahoo.co.in [Department of Materials Engineering, Faculty of Engineering, University of Concepcion, Concepcion (Chile); Mangalaraja, Ramalinga Viswanathan, E-mail: mangal@udec.cl [Department of Materials Engineering, Faculty of Engineering, University of Concepcion, Concepcion (Chile); Siddheswaran, Rajendran [Department of Materials Engineering, Faculty of Engineering, University of Concepcion, Concepcion (Chile); Avila, Ricardo E. [Personal Dosimetry Section, Chilean Nuclear Energy Commission, Santiago (Chile); Ananthakumar, Solaiappan [Materials and Minerals Division, National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum, Kerala (India)

2012-03-01

Growth of multiwalled carbon nanotube (CNT) assemblies by chemical vapour decomposition (CVD) technique was achieved through decomposition of acetylene using iron impregnated montmorillonite (MM) catalysts. Various amounts of iron loaded montmorillonite catalysts were prepared by wet impregnation method and calcined at 450 Degree-Sign C. The catalysts were subjected to X-ray diffraction (XRD) and surface area analyses. Acetylene decomposition at a feed ratio of N{sub 2}:H{sub 2}:C{sub 2}H{sub 2} = 1:1:0.18 was conducted in the presence of iron impregnated montmorillonite catalysts in the CVD reactor for the growth of CNT structures. The role of Fe-activated clay catalyst on the formation of CNT structures has been systematically examined at various temperatures and correlated with the morphological features of CNTs. Catalyst assisted acetylene decomposition results the formation of different carbon nanostructures such as nanotubes, nanofibres and nanoflakes. These clay-CNT products were characterised for their morphological, thermal, qualitative and quantitative analyses. The morphological variations of CNT assemblies reveal Fe-montmorillonite catalysts have high selectivity at given reaction conditions. Thermogravimetric and Raman spectral analyses prove that the CNTs contain a good crystallanity and less structural defects.

Neutron scattering investigation of carbon/carbon composites

International Nuclear Information System (INIS)

Prem, M.; Krexner, G.; Peterlik, H.

2005-01-01

Full text: Carbon/Carbon (C/C) composites, built up from bi-directionally woven fabrics from PAN based carbon fibers, pre-impregnated with phenolic resin followed by pressure curing and carbonization at 1000 o C and a final heat treatment at either 1800 o C or 2400 o C, were investigated by means of small-angle as well as wideangle elastic neutron scattering. Sample orientations arranging the carbon fibers parallel and perpendicular to the incoming beam were examined. Structural features of the composites, i.e. of the fibers as well as the inherently existing pores, are presented and the influence of the heat treatment on the structural properties is discussed. (author)

Impact of impregnation with boron compounds on combustion ...

African Journals Online (AJOL)

This study examined the impacts of varnishing after impregnation with boron compounds on combustion properties of oriental beech. The test samples prepared from oriental beech (Fagus orientalis Lipsky) wood were impregnated according to ASTM D 1413–76–99 with boric acid (Ba) or borax (Bx) using a vacuum ...

Wood construction and magnetic characteristics of impregnated type magnetic wood

International Nuclear Information System (INIS)

Oka, Hideo; Hojo, Atsushi; Seki, Kyoushiro; Takashiba, Toshio

2002-01-01

The results of experiments involving the AC and DC magnetic characteristics of impregnated type magnetic wood were studied by taking into consideration the wood construction and fiber direction. The experimental results show that the sufficient amount of impregnated magnetic fluid varies depending on the fiber direction and length, and the grain face of the wood material. The impregnated type magnetic wood sample that is fully impregnated by magnetic fluid has a 60% saturation magnetization compared to the saturation magnetization of magnetic fluid. Samples for which the wood fiber direction was the same as the direction of the magnetic path had a higher magnetization intensity and permeability

Application in industry and energy production of active carbon/cobalt catalyst for nitrogen oxide neutralization

International Nuclear Information System (INIS)

Mekhandzhiev, D.; Nikolov, R.; Lyutskanov, L.; Dushanov, D.; Lakov, L.

1997-01-01

A new material for neutralization of nitrogen oxides is presented. Two or three metals containing catalysts with a good activity and selectivity towards NO x have been obtained. Preparation of carbon catalysts by deposition of the active phase precursor on the initial carbon material prior to activation is considered as the most promising method. An active carbon-based catalyst (AC/Co) has been synthesized Apricot shells preliminary impregnated with a water-alcohol solution of Co nitrate have been used as initial carbon material. after drying they have been subjected to one-phase steam pyrolysis using a fix-bed reactor. The catalyst thus obtained has a specific surface area (BET) of 53 m 2 g -1 , a favorable mesopore volume/total volume ratio (about 0.85) determined by nitrogen adsorption, a suitable mesopore distribution, about 70% of the mesopores being characterized by r p larger than 25 A and a high dispersion of the Co oxide phase. In addition the catalyst possesses the necessary mechanical resistance. The catalyst has exhibited a high activity with respect to NO x reduction with CO at low temperatures (at 150-250 o C which are the temperatures of industrial flue gases, nO conversion up to 60-95% occurs) and a high selectivity. No presence of H 2 O has been established over the whole temperature range (100-300 o C). An additional advantage of the catalyst is the fact that the amount of CO above 150 o C is lower than the stoichiometric which indicates parallel participation in the process of both the active phase and the support (active carbon) It is also important that the presented catalyst has a low price due to the use of waste products from agriculture and the elimination of special thermal treatment of the supported Co nitrate. There are possibilities of using of other organic wastes from agriculture as well as wastes obtained during flotation of coal. (author)

Adsorption studies of methylene blue and phenol onto vetiver roots activated carbon prepared by chemical activation.

Science.gov (United States)

Altenor, Sandro; Carene, Betty; Emmanuel, Evens; Lambert, Jacques; Ehrhardt, Jean-Jacques; Gaspard, Sarra

2009-06-15

Vetiver roots have been utilized for the preparation of activated carbon (AC) by chemical activation with different impregnation ratios of phosphoric acid, X(P) (gH(3)PO(4)/g precursor): 0.5:1; 1:1 and 1.5:1. Textural characterization, determined by nitrogen adsorption at 77K shows that mixed microporous and mesoporous structures activated carbons (ACs) with high surface area (>1000 m(2)/g) and high pore volume (up to 1.19 cm(3)/g) can be obtained. The surface chemical properties of these ACs were investigated by X-ray photoelectron spectroscopy (XPS) and Boehm titration. Their textural and chemical characteristics were compared to those of an AC sample obtained by steam activation of vetiver roots. Classical molecules used for characterizing liquid phase adsorption, phenol and methylene blue (MB), were used. Adsorption kinetics of MB and phenol have been studied using commonly used kinetic models, i.e., the pseudo-first-order model, the pseudo-second-order model, the intraparticle diffusion model and as well the fractal, BWS (Brouers, Weron and Sotolongo) kinetic equation. The correlation coefficients (R(2)) and the normalized standard deviation Deltaq (%) were determined showing globally, that the recently derived fractal kinetic equation could best describe the adsorption kinetics for the adsorbates tested here, indicating a complex adsorption mechanism. The experimental adsorption isotherms of these molecules on the activated carbon were as well analysed using four isotherms: the classical Freundlich, Langmuir, Redlich-Peterson equations, but as well the newly published deformed Weibull Brouers-Sotolongo isotherm. The results obtained from the application of the equations show that the best fits were achieved with the Brouers-Sotolongo equation and with the Redlich-Peterson equation. Influence of surface functional groups towards MB adsorption is as well studied using various ACs prepared from vetiver roots and sugar cane bagasse. Opposite effects governing MB

Adsorption of Carbon Dioxide, Ammonia, Formaldehyde, and Water Vapor on Regenerable Carbon Sorbents

Science.gov (United States)

Wojtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Wilburn, Monique

2015-01-01

Results are presented on the development of reversible sorbents for the combined carbon dioxide, moisture, and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Furthermore, the current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is nonregenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. In this study, several carbon sorbents were fabricated and tested for simultaneous carbon dioxide, ammonia, formaldehyde, and water sorption. Multiple adsorption/vacuum-regeneration cycles were demonstrated at room temperature, and also the enhancement of formaldehyde sorption by the presence of ammonia in the gas mixture.

Uticaj oksidacije aktivnog uglja sumpornom kiselinom i impregnacije bakar-sulfatom na sorpcionu sposobnost gasnog filtra za zaštitu od dejstva amonijaka / Study of the effects of activated carbon oxidation with sulphuric acid and impregnation with copper sulphate on the protection capacity of gas filters against ammonia

Directory of Open Access Journals (Sweden)

Sretko Ilić

2002-01-01

Full Text Available U radu je istraživana mogućnost poboljšanja kvaliteta aktivnog uglja (AU za upotrebu u sredstvima za ličnu zaštitu respiratornih organa od dejstva amonijaka. Uzorci komercijalnih AU oksidovani su različitim količinama rastvora sumporne kiseline, masenih koncentracija 10% i 15%. Na uzorke AU tretirane kiselinom deponovan je zatim bakar-sulfat, metodom dvostruke impregnacije rastvorom bakar-sulfata do početne vlažnosti uzorka. Impregnisani AU ispitanje u sloju u gasnom filtru prečnika 105 mm, čije su visine imale vrednosti od 29 mm do 41 mm, a uslovi su bill: ulazna koncentracija amonijaka -3,5 mg/dm3 (zapreminska koncentracija 0,5%, protok gasne smeše vazduh-amonijak - 30 dm3/min, relativna vlažnost 70% i ambijentna temperatura. Proboj je detektovan kvalitativno, pomoću indikatorskog papirića safenolftaleinom. AU impregnisan novim postupkom obezbedio je u sloju visine 29 mm vreme proboja 108 min, a 160 min u sloju visine 41 mm. / The objective of this paper has been the study of the possibility to enhance the properties of activated carbon (AC for using it in respiratory protective devices for ammonia removal from the air. The commercial AC samples were oxidized with different amounts of 10% and 15% sulphuric acid solutions. The acid treated AC samples were the loaded with copper sulphate with twofold impregnation by the incipient wetness method. The impregnated AC was tested in a packed bed in the gas filter with a diameter of 105 mm and a bed depth ranging from 29 mm to 41 mm under the following test conditions inlet concentration of ammonia was 3,5 mg/dm3, flow rate of 30 dm3/min at 70% relative humidity and ambient temperature. The breakthrough was detected qualitatively by the phenolphtalein indicator paper. The new impregnated AC reached the breaktrough time of 108 min for a 29 mm bed depth, and 160 min for a bed depth of 41 mm.

PROTECTIVE TREATMENT OF WOOD IMPREGNATING COMPOSITION OF PETROCHEMICAL WASTE

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T. V. Maslakova

2015-01-01

Full Text Available The paper presents results of experimental and theoretical studies aimed at expanding the applications of the copolymers on the basis of the waste styrene production. One of the areas is used as impregnating compositions of wood materials, selection of optimal conditions modification on samples of the most widely used in the industry of wood, such as birch, aspen and other. Studies were conducted to obtain and use an impregnating compositions based on copolymers synthesized from waste products of styrene and the cubic remainder rectification of ethylbenzene (CRRE for the protective treatment of birch wood. Identified physic-chemical characteristics of physical mixtures of copolymers «CORS», «STAM», CRRE at different ratios. Studied the process of modification birch using the method of experiment planning greco-latin square of the fourth order, and the influence of such factors as the temperature of the impregnating composition, the duration of the impregnation, the temperature and duration of thermal treatment on the performance moisture resistance of wood. Were established optimal conditions modification birch wood treated impregnating compositions on the basis of physical mixtures of copolymer «CORS» with CRRE and copolymer «STAM» with CRRE is the mixing ratio 2:1, the duration and temperature of the impregnation 7 h and 95 0C, time and temperature of heat treatment 7 h and 170 0C, respectively. A sealing composition containing CRRE with copolymer «STAM» 1:2 is more preferable, as in the structure of the copolymer «STAM» contains carboxyl and anhydrite group. Thus was justified use for the modification of natural wood impregnating compositions on the basis of physical mixtures of CRRE with copolymers «CORS» and «STAM», which improve the properties of wood, increase moisture and weather resistance more than twice.

Treatment of azo dye-containing wastewater by a Fenton-like process in a continuous packed-bed reactor filled with activated carbon

Energy Technology Data Exchange (ETDEWEB)

Mesquita, Isabel; Matos, Luis C. [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Duarte, Filipa [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); LEPAE - Laboratory for Process, Environmental and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto (Portugal); Maldonado-Hodar, F.J. [Department of Inorganic Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva, 18071 Granada (Spain); Mendes, Adelio [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); LEPAE - Laboratory for Process, Environmental and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto (Portugal); Madeira, Luis M., E-mail: mmadeira@fe.up.pt [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); LEPAE - Laboratory for Process, Environmental and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto (Portugal)

2012-10-30

Highlights: Black-Right-Pointing-Pointer Oxidation with the Fenton's reagent was carried out in a packed-bed reactor. Black-Right-Pointing-Pointer The packed-bed was filled with iron-impregnated activated carbon. Black-Right-Pointing-Pointer The increment of temperature increases the Chicago Sky Blue removal and mineralization. Black-Right-Pointing-Pointer The values of iron leaching were below 0.4 ppm in the outlet effluent. Black-Right-Pointing-Pointer It was possible to reach a dye conversion of 88% in steady-state. - Abstract: In this work, oxidation with a Fenton-like process of a dye solution was carried out in a packed-bed reactor. Activated carbon Norit RX 3 Extra was impregnated with ferrous sulfate and used as catalyst (7 wt.% of iron). The effect of the main operating conditions in the Chicago Sky Blue (CSB) degradation was analyzed. It was found that the increase in temperature leads to a higher removal of the dye and an increased mineralization. However, it also increases the iron leaching, but the values observed were below 0.4 ppm (thus, far below European Union limits). It was possible to reach, at steady-state, a dye conversion of 88%, with a total organic carbon (TOC) removal of ca. 47%, being the reactor operated at 50 Degree-Sign C, pH 3, W{sub cat}/Q = 4.1 g min mL{sup -1} (W{sub cat} is the mass of catalyst and Q the total feed flow rate) and a H{sub 2}O{sub 2} feed concentration of 2.25 mM (for a CSB feed concentration of 0.012 mM). The same performance was reached in three consecutive cycles.

Activated carbon from biomass

Science.gov (United States)

Manocha, S.; Manocha, L. M.; Joshi, Parth; Patel, Bhavesh; Dangi, Gaurav; Verma, Narendra

2013-06-01

Activated carbon are unique and versatile adsorbents having extended surface area, micro porous structure, universal adsorption effect, high adsorption capacity and high degree of surface reactivity. Activated carbons are synthesized from variety of materials. Most commonly used on a commercial scale are cellulosic based precursors such as peat, coal, lignite wood and coconut shell. Variation occurs in precursors in terms of structure and carbon content. Coir having very low bulk density and porous structure is found to be one of the valuable raw materials for the production of highly porous activated carbon and other important factor is its high carbon content. Exploration of good low cost and non conventional adsorbent may contribute to the sustainability of the environment and offer promising benefits for the commercial purpose in future. Carbonization of biomass was carried out in a horizontal muffle furnace. Both carbonization and activation were performed in inert nitrogen atmosphere in one step to enhance the surface area and to develop interconnecting porosity. The types of biomass as well as the activation conditions determine the properties and the yield of activated carbon. Activated carbon produced from biomass is cost effective as it is easily available as a waste biomass. Activated carbon produced by combination of chemical and physical activation has higher surface area of 2442 m2/gm compared to that produced by physical activation (1365 m2/gm).

[Study on influence between activated carbon property and immobilized biological activated carbon purification effect].

Science.gov (United States)

Wang, Guang-zhi; Li, Wei-guang; He, Wen-jie; Han, Hong-da; Ding, Chi; Ma, Xiao-na; Qu, Yan-ming

2006-10-01

By means of immobilizing five kinds of activated carbon, we studied the influence between the chief activated carbon property items and immobilized bioactivated carbon (IBAC) purification effect with the correlation analysis. The result shows that the activated carbon property items which the correlation coefficient is up 0.7 include molasses, abrasion number, hardness, tannin, uniform coefficient, mean particle diameter and effective particle diameter; the activated carbon property items which the correlation coefficient is up 0.5 include pH, iodine, butane and tetrachloride. In succession, the partial correlation analysis shows that activated carbon property items mostly influencing on IBAC purification effect include molasses, hardness, abrasion number, uniform coefficient, mean particle diameter and effective particle diameter. The causation of these property items bringing influence on IBAC purification is that the activated carbon holes distribution (representative activated carbon property item is molasses) provides inhabitable location and adjust food for the dominance bacteria; the mechanical resist-crash property of activated carbon (representative activated carbon property items: abrasion number and hardness) have influence on the stability of biofilm; and the particle diameter size and distribution of activated carbon (representative activated carbon property items: uniform coefficient, mean particle diameter and effective particle diameter) can directly affect the force of water in IBAC filter bed, which brings influence on the dominance bacteria immobilizing on activated carbon.

Redox Deposition of Nanoscale Metal Oxides on Carbon for Next-Generation Electrochemical Capacitors

Science.gov (United States)

2013-01-01

conductive carbon supports. Many pro- tocols, including electrodeposition ,17 vapor deposi- tion,18 impregnation/decomposition,19 and solgel chemistry20 have...can be mitigated by dispersing the oxide on high-surface-area carbons (via solgel, impregnation, CVD, or electrodeposition methods), a strategy that...et al. Christopher Chervin is a staff scientist at the NRL, where his research focuses on redesigning cathodes for metalair batteries and exploring

Radiation hardenable impregnating agents for the consolidating conservation of wooden objects

International Nuclear Information System (INIS)

Schaudy, R.

1985-01-01

Radiation hardenable impregnating agents offer some advantages over the conventional agents. At the author's institution objects up to 110 cm length can be impregnated for conservation. More than 200 monomers and resins have been investigated. The procedure of impregnation is outlined and some kinds of wooden objects conserved in this way listed. (G.W.)

21 CFR 529.1003 - Flurogestone acetate-impregnated vaginal sponge.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Flurogestone acetate-impregnated vaginal sponge... § 529.1003 Flurogestone acetate-impregnated vaginal sponge. (a) Specifications. Each vaginal sponge... ewes during their normal breeding season. (2) Limitations. Using applicator provided, insert sponge...

Effects of pore sizes and oxygen-containing functional groups on desulfurization activity of Fe/NAC prepared by ultrasonic-assisted impregnation

Energy Technology Data Exchange (ETDEWEB)

Shu, Song [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); Guo, Jia-Xiu, E-mail: guojiaxiu@scu.edu.cn [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China); Sichuan Provincial Environmental Protection Environmental Catalysis and Materials Engineering Technology Center, Chengdu 610065, Sichuan (China); Liu, Xiao-Li [National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China); Wang, Xue-Jiao [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); Yin, Hua-Qiang [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China); Sichuan Provincial Environmental Protection Environmental Catalysis and Materials Engineering Technology Center, Chengdu 610065, Sichuan (China); Luo, De-Ming [National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China)

2016-01-01

Graphical abstract: - Highlights: • Fe/NAC-60 exhibits the best desulfurization activity. • Different oscillation time can change surface area and pore volume of catalysts. • Ultrasonic oscillation increases Fe dispersion on carrier and effective pores. • Pore sizes play a crucial role during the SO{sub 2} removal. - Abstract: A series of Fe-loaded activated carbons treated by HNO{sub 3} (Fe/NAC) were prepared by incipient impregnation method with or without ultrasonic assistance and characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy with energy disperse spectroscope (SEM-EDS), transmission electron microscopy (TEM) and N{sub 2} adsorption/desorption. The desulfurization activities were evaluated at a fixed bed reactor under a mixed gas simulated from flue gas. The results showed that desulfurization activity from excellent to poor is as follows: Fe/NAC-60 > Fe/NAC-80 > Fe/NAC-30 > Fe/NAC-15 > Fe/NAC-0 > Fe/NAC-100 > NAC. Fe/NAC-60 exhibits the best desulfurization activity and has breakthrough sulfur capacity of 319 mg/g and breakthrough time of 540 min. The introduction of ultrasonic oscillation does not change the form of Fe oxides on activated carbon but can change the dispersion and relative contents of Fe{sub 3}O{sub 4}. The types of oxygen-containing functional groups have no obvious change for all samples but the texture properties show some differences when they are oscillated for different times. The fresh Fe/NAC-60 has a surface area of 1045 m{sup 2}/g and total pore volume of 0.961 cm{sup 3}/g with micropore volume of 0.437 cm{sup 3}/g and is larger than Fe/NAC-0 (823 m{sup 2}/g, 0.733 and 0.342 cm{sup 3}/g). After desulfurization, surface area and pore volume of all samples decrease significantly, and those of the exhausted Fe/NAC-60 decrease to 233 m{sup 2}/g and 0.481 cm{sup 3}/g, indicating that some byproducts deposit on surface to cover pores. Pore size distribution

Physicochemical properties of vanadium impregnated Al-PILCs: Effect of vanadium source

Energy Technology Data Exchange (ETDEWEB)

Balci, Suna, E-mail: sunabalci@gazi.edu.tr; Tecimer, Aylin

2015-03-01

Graphical abstract: - Highlights: • Vanadium was incorporated into Al-PILC using NaVO{sub 3} or VOSO{sub 4}·3H{sub 2}O precursors by wet impregnation, washing after wet impregnation and impregnation from solution methods. • The layered structure of the supports was retained after the vanadium incorporation. • Incorporation took place both by settling and ion exchange mechanism with the treatment VOSO{sub 4}·3H{sub 2}O precursor while settling was dominant in the use of NaVO{sub 3} precursor. • Treatment with VOSO{sub 4}·3H{sub 2}O which was acidic in solution resulted in more structural deformation. • V{sub 2}O{sub 5} and VO{sub 2} were found as the major oxide forms on the impregnated samples. Loading of vanadyl sulfate hydrate (VOSO{sub 4}·H{sub 2}O) resulted in higher V/Si ratio. Most of the vanadium was bonded in +5 oxide form. • Changes in the FTIR signals after vanadium incorporation caused by Brønsted and Lewis sites, silanol, water and vanadium vibrations were occured. • Dehydroxylation of the structure took place around 300 °C. Samples obtained by impregnation and washing after wet impregnation methods resulted in similar mass losses and the wet impregnated sample showed the highest mass loss among the impregnated samples. - Summary: Clay from the Middle Anatolian previously pillared by Al{sub 13}-Keggin ions and then calcined at 300 °C (Al-PILC) was impregnated with aqueous solutions of vanadium precursors by impregnation from solution (I), wet impregnation (WI) and washing after wet impregnation (WWI) methods. The crystal and textural properties were evaluated by X-ray powder diffraction (XRD), nitrogen sorption and transmission electron microscopy (TEM) images. Vanadium incorporation into the Al-PILC resulted decreases in the basal spacing from 1.75 nm to 1.35 nm with the preserved typical layered structure. The use of sodium metavanadate (NaVO{sub 3}) as the source and the impregnation from solution as the incorporation method

Nitrogen doped activated carbon from pea skin for high performance supercapacitor

Science.gov (United States)

Ahmed, Sultan; Ahmed, Ahsan; Rafat, M.

2018-04-01

In this work, nitrogen doped porous carbon (NDC) has been synthesized employing a facile two-step process. Firstly, carbon precursor (pea skin) was heated with melamine (acting as nitrogen source) followed by activation with KOH in different ratios. The dependence of porosity and nitrogen content on impregnation ratio was extensively studied. Other textural properties of prepared NDC sample were studied using standard techniques of material characterization. The electrochemical performance of NDC sample as an electrode was studied in two-electrode symmetric supercapacitor system. 1 M LiTFSI (lithium bis-trifluoromethanesulfonimide) solution in IL EMITFSI (1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), was used as electrolyte. It was found that the fabricated supercapacitor cell offers high values of specific capacitance (141.1 F g‑1), specific energy (19.6 Wh kg‑1) and specific power (25.4 kW kg‑1) at current density of 1.3 A g‑1. More importantly, the fabricated supercapacitor cell shows capacitance retention of ∼75%, for more than 5000 cycles. The enhanced performance of NDC sample is primarily due to large surface area with favorable surface structure (contributing to double layer capacitance) and presence of nitrogen functionalities (contributing to pseudo-capacitance). Such important features make the synthesized NDC sample, an attractive choice for electrode material in high performance supercapacitor.

Electrochemical Oxidation of EDTA in Nuclear Wastewater Using Platinum Supported on Activated Carbon Fibers

Science.gov (United States)

Zhao, Bo; Zhu, Wenkun; Mu, Tao; Hu, Zuowen; Duan, Tao

2017-01-01

A novel Pt/ACF (Pt supported on activated carbon fibers) electrode was successfully prepared with impregnation and electrodeposition method. Characterization of the electrodes indicated that the Pt/ACF electrode had a larger effective area and more active sites. Electrochemical degradation of ethylenediaminetetra-acetic acid (EDTA) in aqueous solution with Pt/ACF electrodes was investigated. The results showed that the 3% Pt/ACF electrode had a better effect on EDTA removal. The operational parameters influencing the electrochemical degradation of EDTA with 3% Pt/ACF electrode were optimized and the optimal removal of EDTA and chemical oxygen demand (COD) were 94% and 60% after 100 min on condition of the electrolyte concentration, initial concentration of EDTA, current density and initial value of pH were 0.1 mol/L, 300 mg/L, 40 mA/cm2 and 5.0, respectively. The degradation intermediates of EDTA in electrochemical oxidation with 3% Pt/ACF electrode were identified by gas chromatography-mass spectrum (GC-MS). PMID:28754016

Electrochemical Oxidation of EDTA in Nuclear Wastewater Using Platinum Supported on Activated Carbon Fibers.

Science.gov (United States)

Zhao, Bo; Zhu, Wenkun; Mu, Tao; Hu, Zuowen; Duan, Tao

2017-07-21

A novel Pt/ACF (Pt supported on activated carbon fibers) electrode was successfully prepared with impregnation and electrodeposition method. Characterization of the electrodes indicated that the Pt/ACF electrode had a larger effective area and more active sites. Electrochemical degradation of ethylenediaminetetra-acetic acid (EDTA) in aqueous solution with Pt/ACF electrodes was investigated. The results showed that the 3% Pt/ACF electrode had a better effect on EDTA removal. The operational parameters influencing the electrochemical degradation of EDTA with 3% Pt/ACF electrode were optimized and the optimal removal of EDTA and chemical oxygen demand (COD) were 94% and 60% after 100 min on condition of the electrolyte concentration, initial concentration of EDTA, current density and initial value of pH were 0.1 mol/L, 300 mg/L, 40 mA/cm² and 5.0, respectively. The degradation intermediates of EDTA in electrochemical oxidation with 3% Pt/ACF electrode were identified by gas chromatography-mass spectrum (GC-MS).

Using copper hexacyanoferrate (II) impregnated zeolite for cesium removal from radioactive liquid waste

International Nuclear Information System (INIS)

Fumio, K.; Kenji, M.

1982-01-01

Experiments were performed to obtain fundamental data on cesium ion removal characteristics of metal hexacyanoferrate (II) impregnated zeolite in radioactive liquid waste containing a large amount of sodium sulfate. Copper hexacyanoferrate (II) impregnated zeolite (CuFZ) was prepared and showed a high selectivity for cesium ion. The material was suitable for use in an ion exchange column. This exchanger could selectively and efficiently remove the cesium even if there is 15 wt% Na 2 SO 4 in the solution. Cesium removal ability and stability of CuFZ were excellent over a wide pH range between 1.5 and 10. The cesium ion exchange ability was not influenced by the presence of the alkali metal ions, calcium and magnesium, and carbonate ions even at concentrations 25 times greater than the cesium ion. However, since ammonium ion behaves similarly to cesium ion and interrupts latter ion adsorption, the presence of ammonium ion is not desirable. The CuFZ offers the possibility of separating and removing cesium from liquid wastes produced in facilities handling radioactive materials

Impregnation transition in a powder

Science.gov (United States)

Raux, Pascal; Cockenpot, Heloise; Quere, David; Clanet, Christophe

2011-11-01

When an initially dry pile of micrometrical grains comes into contact with a liquid, one can observe different behaviors, function of the wetting properties. If the contact angle with the solid is low, the liquid will invade the pile (impregnation), while for higher contact angles, the grains will stay dry. We present an experimental study of this phenomenon: a dry pile of glass beads is deposed on the liquid surface, and we vary the contact angle of the liquid on the grains. We report a critical contact angle below which impregnation always occurs, and develop a model to explain its value. Different parameters modifying this critical contact angle are also investigated. Collaboration with Marco Ramaioli, Nestle Research Center, Lausanne, Switzerland.

Fiber-reinforced ceramic matrix composites processed by a hybrid technique based on chemical vapor infiltration, slurry impregnation and spark plasma sintering

International Nuclear Information System (INIS)

Magnant, J.; Pailler, R.; Le Petitcorps, Y.; Maille, L.; Guette, A.; Marthe, J.

2013-01-01

Fabrication of multidirectional continuous carbon and silicon carbide fiber reinforced ceramic matrix composites (CMC) by a new short time hybrid process was studied. This process is based, first, on the deposition of fiber interphase and coating by chemical vapor infiltration, next, on the introduction of silicon nitride powders into the fibrous preform by slurry impregnation and, finally, on the densification of the composite by liquid phase spark plasma sintering (LP-SPS). The homogeneous introduction of the ceramic charges into the multidirectional fiber pre-forms was realized by slurry impregnation from highly concentrated and well-dispersed aqueous colloid suspensions. The chemical degradation of the carbon fibers during the fabrication was prevented by adapting the sintering pressure cycle. The composites manufactured are dense. Microstructural analyses were conducted to explain the mechanical properties achieved. One main important result of this study is that LP-SPS can be used in some hybrid processes to densify fiber reinforced CMC. (authors)

High-activity MgO-supported CoMo Hydrodesulfurization Catalysts Prepared by Non-aqueous Impregnation

Czech Academy of Sciences Publication Activity Database

Kaluža, Luděk; Gulková, Daniela; Vít, Zdeněk; Zdražil, Miroslav

2015-01-01

Roč. 162, JAN 2015 (2015), s. 430-436 ISSN 0926-3373 R&D Projects: GA ČR GAP106/11/0902 Institutional support: RVO:67985858 Keywords : CoMo/MgO * benzothiophene hydrodesulfurization * non-aqueous impregnation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 8.328, year: 2015

Activated carbons and gold

International Nuclear Information System (INIS)

McDougall, G.J.; Hancock, R.D.

1980-01-01

The literature on activated carbon is reviewed so as to provide a general background with respect to the effect of source material and activation procedure on carbon properties, the structure and chemical nature of the surface of the activated carbon, and the nature of absorption processes on carbon. The various theories on the absorption of gold and silver from cyanide solutions are then reviewed, followed by a discussion of processes for the recovery of gold and silver from cyanide solutions using activated carbon, including a comparison with zinc precipitation

Characteristics of scandate-impregnated cathodes with sub-micron scandia-doped matrices

International Nuclear Information System (INIS)

Yuan Haiqing; Gu Xin; Pan Kexin; Wang Yiman; Liu Wei; Zhang Ke; Wang Jinshu; Zhou Meiling; Li Ji

2005-01-01

We describe in this paper scandate-impregnated cathodes with sub-micron scandia-doped tungsten matrices having an improved uniformity of the Sc distribution. The scandia-doped tungsten powders were made by both liquid-solid doping and liquid-liquid doping methods on the basis of previous research. By improving pressing, sintering and impregnating procedures, we have obtained scandate-impregnated cathodes with a good uniformity of the Sc 2 O 3 - distribution. The porosity of the sub-micron structure matrix and content of impregnants inside the matrix are similar to those of conventionally impregnated cathodes. Space charge limited current densities of more than 30 A/cm 2 at 850 deg. C b have been obtained in a reproducible way. The current density continuously increases during the first 2000 h life test at 950 deg. C b with a dc load of 2 A/cm 2 and are stable for at least 3000 h

Effects of impregnation with boron compounds on the surface ...

African Journals Online (AJOL)

Liebl.) which met the requirements of ASTM D 358 were impregnated according to ASTM D 1413 with boric acid (Ba) and borax (Bx) by vacuum technique. After impregnation, surfaces were coated with cellulosic, synthetic, polyurathane, water-based, acrylic and acid hardening varnishes in accordance with ASTM D 3023 ...

Study on Pt-structured anodic alumina catalysts for catalytic combustion of toluene: Effects of competitive adsorbents and competitive impregnation methods

Science.gov (United States)

Zhang, Qi; Luan, Hongjuan; Li, Tao; Wu, Yongqiang; Ni, Yanhui

2016-01-01

Novel competitive impregnation methods were used to prepare high dispersion Pt-structured anodic alumina catalysts. It is found that competitive adsorbents owning different acidity result in different Pt loading amount and also exert great effects on Pt distribution, particle size and redox ability. The suitable adsorption ability of lactic acid led to its best activity for catalytic combustion of toluene. Co-competitive and pre-competitive impregnation methods were also compared and the mechanisms of two competitive methods were proposed. Co-competitive impregnation made Pt distribute more uniformly through pore channels and resulted in better catalytic activity, because of the weaker spatial constraint effect of lactic acid. Furthermore, the optimized Pt-structured anodic alumina catalyst also showed a good chlorine-resistance under moisture atmosphere, because water could promote the reaction of dichloromethane (DCM) transformation and clean chloride by-products to release more active sites.

Synthesis, Characterization, and Impregnation of Some Ionic Liquids on Polymer Membrane for Separation of Carbon Dioxide from Its Mixture with Methane

Directory of Open Access Journals (Sweden)

T. T. L. Bui

2018-03-01

Full Text Available Some 1-alkyl-3-methylimidazolium-based ionic liquids were synthesized, characterized, and immobilized on membranes to form supported ionic liquid membranes. The supported ionic liquid membranes were characterized by SEM. The initial transmembrane pressures were investigated for each type of impregnated membrane. The CO2/CH4 single gas and mixed gas permeability (CO2 and CH4 have been investigated. The results showed that the CO2/CH4 ideal selectivities and mixed gas selectivities reached 15.45 – 23.9 and 13.91 – 22.82, respectively (equivalent to separation yields of 93.3 – 95.98 %.mThe 1-alkyl-3-methylimidazolium acetate impregnated membrane leads to a slightly lowermCO2/CH4 selectivity, however, this ionic liquid is stable, free of halogen and has a low price. The impregnated membranes prepared from polyvinylidene fluoride are more stablemthan those from polyethersulfone support, and have a higher affinity for CO2 compared to other gas. The obtained high CO2/CH4 selectivities indicate that immobilized membranes can be used for CO2 separation processes.

Carbon activity meter

International Nuclear Information System (INIS)

Roy, P.; Krankota, J.L.

1975-01-01

A carbon activity meter utilizing an electrochemical carbon cell with gaseous reference electrodes having particular application for measuring carbon activity in liquid sodium for the LMFBR project is described. The electrolyte container is electroplated with a thin gold film on the inside surface thereof, and a reference electrode consisting of CO/CO 2 gas is used. (U.S.)

Activated, coal-based carbon foam

Science.gov (United States)

Rogers, Darren Kenneth; Plucinski, Janusz Wladyslaw

2004-12-21

An ablation resistant, monolithic, activated, carbon foam produced by the activation of a coal-based carbon foam through the action of carbon dioxide, ozone or some similar oxidative agent that pits and/or partially oxidizes the carbon foam skeleton, thereby significantly increasing its overall surface area and concurrently increasing its filtering ability. Such activated carbon foams are suitable for application in virtually all areas where particulate or gel form activated carbon materials have been used. Such an activated carbon foam can be fabricated, i.e. sawed, machined and otherwise shaped to fit virtually any required filtering location by simple insertion and without the need for handling the "dirty" and friable particulate activated carbon foam materials of the prior art.

Supercritical CO2 impregnation of polyethylene components for medical purposes

Directory of Open Access Journals (Sweden)

Gamse Thomas

2007-01-01

Full Text Available Modem hip and knee endoprosthesis are produced in titanium and to reduce the friction at the contact area polymer parts, mainly ultra-high molecular weight polyethylene (UHMW-PE, are installed. The polyethylene is impregnated with a-tocopherol (vitamin E before processing for remarkable decrease of oxidative degradation. Cross linked UHMW-PE offers much higher stability, but a-tocopherol cannot be added before processing, because a-tocopherol hinders the cross linking process accompanied by a heavy degradation of the vitamin. The impregnation of UHMW-PE with a-tocopherol has to be performed after the cross linking process and an accurate concentration has to be achieved over the cross section of the whole material. In the first tests UHMW-PE-cubes were stored in pure a-tocopherol under inert atmosphere at temperatures from 100 to 150 °C resulting in a high mass fraction of a-tocopherol in the edge zones and no constant concentration over the cross section. For better distribution and for regulating the mass fraction of a-tocopherol in the cross linked UHMW-PE material supercritical CO2 impregnation tests were investigated. Again UHMW-PE-cubes were impregnated in an autoclave with a-tocopherol dissolved in supercritical CO2 at different pressures and temperatures with variable impregnation times and vitamin E concentrations. Based on the excellent results of supercritical CO2 impregnation standard hip and knee cups were stabilized nearly homogeneously with varying mass fraction of a-tocopherol.

Impregnation of soft biological specimens with thermosetting resins and elastomers.

Science.gov (United States)

von Hagens, G

1979-06-01

A new method for impregnation of biological specimens with thermosetting resins and elastomers is described. The method has the advantage that the original relief of the surface is retained. The impregnation is carried out by utilizing the difference between the high vapor tension of the intermedium (e.g., methylene chloride) and the low vapor tension of the solution to be polymerized. After impregnation, the specimen is subject to polymerization conditions without surrounding embedding material. The optical and mechanical properties can be selected by proper choice from various kinds of resins and different procedures, for example, by complete or incomplete impregnation. Acrylic resins, polyester resins, epoxy resins, polyurethanes and silicone rubber have been found suitable for the method. Excellent results have been obtained using transparent silicone rubber since after treatment the specimens are still flexible and resilient, and have retained their natural appearance.

X-ray initiated polymerization of wood impregnants

Energy Technology Data Exchange (ETDEWEB)

Cleland, Marshall R.; Galloway, Richard A. [IBA Industrial, Inc., Edgewood, NY (United States); Berejka, Anthony J. [Ionicorp, Huntington, NY 11743 (United States)], E-mail: berejka@msn.com; Montoney, Daniel [Strathmore Products, Syracuse, NY (United States); Driscoll, Mark; Smith, Leonard; Scott Larsen, L. [State University of New York, SUNY-ESF, Syracuse, NY (United States)

2009-07-15

X-rays, derived from a high energy, high-current electron beam (EB), initiated in-situ polymerization of a unique class of monomers that were found to penetrate the cell walls of wood. X-rays initiated an auto-catalytic acrylic polymerization and penetrated through thick pieces of wood. The final cured product having the polymerizate, a polymer, both in the wood cell lumens and in the cell walls is called wood impregnated with a wood-polymer penetrant (WPP). The controlled lower dose rate of X-rays overcame disproportionation encountered when using higher dose-rate electron beam initiation. With X-rays, the in-situ polymerization took place in one exposure of modest dose. With EB, multiple passes were needed to avoid excessive heat build-up and monomer volatilization. Having entered the cell walls of the wood and then being polymerized within the cell walls, these radiation-cured unique monomers imparted outstanding dimensional stability upon exposure of the impregnated wood to humidity cycling. The preferred monomer system was also chemically modified prior to impregnation with agents that would remain in the wood and prevent the growth of fungi and other microbials. This technique differs from historic uses of monomers that merely filled the lumens of the wood (historic wood-polymer composites), which are only suitable for indoor use. The WPP impregnated wood that was either X-ray cured or EB cured demonstrated enhanced structural properties, dimensional stability, and decay resistance.

X-ray initiated polymerization of wood impregnants

International Nuclear Information System (INIS)

Cleland, Marshall R.; Galloway, Richard A.; Berejka, Anthony J.; Montoney, Daniel; Driscoll, Mark; Smith, Leonard; Scott Larsen, L.

2009-01-01

X-rays, derived from a high energy, high-current electron beam (EB), initiated in-situ polymerization of a unique class of monomers that were found to penetrate the cell walls of wood. X-rays initiated an auto-catalytic acrylic polymerization and penetrated through thick pieces of wood. The final cured product having the polymerizate, a polymer, both in the wood cell lumens and in the cell walls is called wood impregnated with a wood-polymer penetrant (WPP). The controlled lower dose rate of X-rays overcame disproportionation encountered when using higher dose-rate electron beam initiation. With X-rays, the in-situ polymerization took place in one exposure of modest dose. With EB, multiple passes were needed to avoid excessive heat build-up and monomer volatilization. Having entered the cell walls of the wood and then being polymerized within the cell walls, these radiation-cured unique monomers imparted outstanding dimensional stability upon exposure of the impregnated wood to humidity cycling. The preferred monomer system was also chemically modified prior to impregnation with agents that would remain in the wood and prevent the growth of fungi and other microbials. This technique differs from historic uses of monomers that merely filled the lumens of the wood (historic wood-polymer composites), which are only suitable for indoor use. The WPP impregnated wood that was either X-ray cured or EB cured demonstrated enhanced structural properties, dimensional stability, and decay resistance.

Implementation of carbon nanomodification for sorption materials

Directory of Open Access Journals (Sweden)

Babkin Alexander

2017-01-01

Full Text Available The article addresses the urgent task of improving the adsorption capacity and expanding the scope of application for commonly used industrial sorbents – activated carbons and synthetic zeolites. Among a variety of methods for modifying these sorbents, more attention is now being given to techniques that employ carbon nanomaterials. This is due to the unique properties of nanostructures – developed surface, availability of active functional groups, etc. In the present work, the classic materials – NWC coconut shell activated carbon and synthetic NaX zeolite – were chosen as initial sorbent samples to be modified. The authors developed a process flowsheet for the carbon nanomodification, which contains the following main stages: preparation of a catalytic mixture solution under given temperature conditions, impregnation of porous materials using the obtained solution, and drying and synthesis of carbon nanotubes via chemical vapor deposition. The proposed technological line consists of a reactor for synthesis of carbon nanotubes, the patented design of which will allow for simultaneously modifying in an effective way different types of materials. As a result, the layer of carbon nanostructures, the quality of which can be varied by changing the conditions of the modification procedure, is formed on the substrate surface.

Laser incising of wood: Impregnation of columns with water-soluble dye

International Nuclear Information System (INIS)

Hattori, N.; Ando, K.; Kitayama, S.; Nakamura, Y.

1994-01-01

To know whether or not laser incising is a useful pre-treatment technique in impregnating a chemical fluid into lumber, pin holes were made in columns of hinoki (Chamaecyparis obtusa Endl.), sugi (Cryptomeria japonica D. Don), karamatsu (Larix leptolepis Gordon) and douglas-fir (Pseudo-tsuga menziesii Franco) with 1.7 kW CO2 laser, and a water-soluble dye was impregnated into these columns with a local pressure impregnation device. Retentions, and lengths and widths of penetrations from each hole were measured quantitatively. Referring to the results of the preparatory experiment mentioned above, incising patterns for sugi and douglas-fir were designed, and the same water-soluble dye was impregnated into the laser-incised columns as well as into non-incised ones with the vacuum-pressure method to obtain penetrated layers with the target depths completely. As a result, a retention of 200 kg/m3 of dye could be achieved for a column of douglas-fir even if it is a species difficult to impregnate. The penetrated layer also could be formed completely at the depth of the laser incision. Therefore, it is concluded that laser incising can be used for the pre-treatment before impregnation of wood columns. (author)

Preparation of Carbon-Platinum-Ceria and Carbon-Platinum-Cerium catalysts and its application in Polymer Electrolyte Fuel Cell: Hydrogen, Methanol, and Ethanol

Science.gov (United States)

Guzman Blas, Rolando Pedro

This thesis is focused on fuel cells using hydrogen, methanol and ethanol as fuel. Also, in the method of preparation of catalytic material for the anode: Supercritical Fluid Deposition (SFD) and impregnation method using ethylenediaminetetraacetic acid (EDTA) as a chelating agent. The first part of the thesis describes the general knowledge about Hydrogen Polymer Exchange Membrane Fuel Cell (HPEMFC),Direct Methanol Fuel Cell (DMFC) and Direct Ethanol Fuel Cell (DEFC), as well as the properties of Cerium and CeO2 (Ceria). The second part of the thesis describes the preparation of catalytic material by Supercritical Fluid Deposition (SFD). SFD was utilized to deposit Pt and ceria simultaneously onto gas diffusion layers. The Pt-ceria catalyst deposited by SFD exhibited higher methanol oxidation activity compared to the platinum catalyst alone. The linear sweep traces of the cathode made for the methanol cross over study indicate that Pt-Ceria/C as the anode catalyst, due to its better activity for methanol, improves the fuel utilization, minimizing the methanol permeation from anode to cathode compartment. The third and fourth parts of the thesis describe the preparation of material catalytic material Carbon-Platinum-Cerium by a simple and cheap impregnation method using EDTA as a chelating agent to form a complex with cerium (III). This preparation method allows the mass production of the material catalysts without additional significant cost. Fuel cell polarization and power curves experiments showed that the Carbon-Platinum-Cerium anode materials exhibited better catalytic activity than the only Vulcan-Pt catalysts for DMFC, DEFC and HPEMFC. In the case of Vulcan-20%Pt-5%w Cerium, this material exhibits better catalytic activity than the Vulcan-20%Pt in DMFC. In the case of Vulcan-40% Pt-doped Cerium, this material exhibits better catalytic activity than the Vulcan-40% Pt in DMFC, DEFC and HPEMFC. Finally, I propose a theory that explains the reason why the

Ruthenium oxide/carbon composites with microporous or mesoporous carbon as support and prepared by two procedures. A comparative study as supercapacitor electrodes

International Nuclear Information System (INIS)

Pico, F.; Morales, E.; Fernandez, J.A.; Centeno, T.A.; Ibanez, J.; Rojas, R.M.; Amarilla, J.M.; Rojo, J.M.

2009-01-01

Composites are prepared by deposition of nanoparticles of RuO 2 .xH 2 O (1-4 nm) on two carbons: microporous carbon (1.3 nm of average micropore size) and mesoporous carbon (11 nm of average mesopore size). Two-preparation procedures are used: (i) procedure A consisting of repetitive impregnations of the carbons with RuCl 3 .0.5H 2 O solutions, and (ii) procedure B based on impregnation of the carbons with Ru(acac) 3 vapour. The procedure B leads to supported RuO 2 .xH 2 O particles that appear more crystalline than those obtained by the procedure A. Specific capacitance and specific surface area of the composites are discussed as functions of the RuO 2 content, and different dependences for the composites derived from the two carbons are found. Mesoporous carbon is better support than microporous carbon. Procedure A leads to supported RuO 2 .xH 2 O particles with higher specific capacitance than the particles deposited by procedure B

Ruthenium oxide/carbon composites with microporous or mesoporous carbon as support and prepared by two procedures. A comparative study as supercapacitor electrodes

Energy Technology Data Exchange (ETDEWEB)

Pico, F. [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC), Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049-Madrid (Spain); Morales, E. [Instituto de Ciencia y Tecnologia de Polimeros (ICTP), CSIC, Juan de la Cierva 3, E-28006-Madrid (Spain); Fernandez, J.A.; Centeno, T.A. [Instituto Nacional del Carbon (INCAR), CSIC, Francisco Pintado Fe 26, E-33011-Oviedo (Spain); Ibanez, J. [Centro Nacional de Investigaciones Metalurgicas (CENIM), CSIC, Avda. Gregorio del Amo 8, E-28040-Madrid (Spain); Rojas, R.M.; Amarilla, J.M. [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC), Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049-Madrid (Spain); Rojo, J.M. [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC), Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049-Madrid (Spain)], E-mail: jmrojo@icmm.csic.es

2009-03-01

Composites are prepared by deposition of nanoparticles of RuO{sub 2}.xH{sub 2}O (1-4 nm) on two carbons: microporous carbon (1.3 nm of average micropore size) and mesoporous carbon (11 nm of average mesopore size). Two-preparation procedures are used: (i) procedure A consisting of repetitive impregnations of the carbons with RuCl{sub 3}.0.5H{sub 2}O solutions, and (ii) procedure B based on impregnation of the carbons with Ru(acac){sub 3} vapour. The procedure B leads to supported RuO{sub 2}.xH{sub 2}O particles that appear more crystalline than those obtained by the procedure A. Specific capacitance and specific surface area of the composites are discussed as functions of the RuO{sub 2} content, and different dependences for the composites derived from the two carbons are found. Mesoporous carbon is better support than microporous carbon. Procedure A leads to supported RuO{sub 2}.xH{sub 2}O particles with higher specific capacitance than the particles deposited by procedure B.

A Mathematical Model of Repeated Impregnation of Porous Bodies with Solutions of Polymers

Directory of Open Access Journals (Sweden)

I. V. Glebov

2015-01-01

Full Text Available The paper describes basic methods of impregnating porous bodies with solutions of polymers and their use to manufacture prepregs. It also describes the existing methods of manufacturing multilayer prepregs to produce aerospace coating of the spacecraft "Soyuz". It is shown that these prepregs have to meet high requirements for the content of the polymer, as compared with other composite materials, about 35 - 40% of the mass. Methods used for their manufacturing are long-term and non-controllable. The assumption is made that using the vacuum impregnation technology of a woven material will allow to accelerate the manufacturing process of these prepregs and improve their quality.In reviewing the technical literature have been found works on modeling the processes of impregnation, but they are aimed only at studying the speed of the woven material impregnation by various fluids and determining the time of impregnation. There were no models found to define prepreg parameters during the process of multiple impregnations. The aim of this work is to develop the simple mathematical model, which enables us to predict the polymer content of volatile products in the prepreg after each cycle of multiple impregnation of woven material with a solution of the polymer.To consider the vacuum impregnation method are used the prepregs based on silica and silica-nylon stitch-bonding fabric and bakelite varnish LBS-4 containing 50 - 60% of phenol resin and the solvent with minor impurities of pure phenol and water, as an example. To describe the process of vacuum impregnation of the porous work-piece is developed a mathematical description of the process of filling the porous space of the material with a varnish. It is assumed that the varnish components fill the porous space of the material in the same proportion as they are contained in the varnish.It is shown that a single impregnation cannot ensure the content of phenol resin in the prepreg over 32%, which does

Physicochemical properties of metal-doped activated carbons and relationship with their performance in the removal of SO2 and NO

International Nuclear Information System (INIS)

Gao Xiang; Liu Shaojun; Zhang Yang; Luo Zhongyang; Cen Kefa

2011-01-01

Research highlights: → Cu and Fe were partly reduced by carbon during preparation. → Metal-involved SO 2 removal pathways were catalytic oxidation, reaction and adsorption. → Good performances of SO 2 and NO removal depended on the metal redox pairs. - Abstract: Several metal-doped activated carbons (Fe, Co, Ni, V, Mn, Cu and Ce) were prepared and characterized. The results of N 2 adsorption-desorption, X-ray diffraction, and X-ray photoelectron spectroscopy indicated that some metals (Cu and Fe) were partly reduced by carbon during preparation. Activity tests for the removal of SO 2 and the selective catalytic reduction of NO with ammonia were carried out. Due to different physicochemical properties, different pathways for the SO 2 removal had been put out, i.e., catalytic oxidation, direct reaction and adsorption. This classification depended on the standard reduction potentials of metal redox pairs. Samples impregnated with V, Ce and Cu showed good activity for NO reduction by NH 3 , which was also ascribed to the reduction potential values of metal redox pairs. Ce seemed to be a promising alternative to V due to the higher activity in NO reduction and the nontoxic property. A metal cation which could easily convert between the two valences seemed to be crucial to the good performance of both SO 2 and NO removal, just like V and Cu.

Field evaluation of spatial repellency of metofluthrin-impregnated plastic strips against Anopheles gambiae complex in Bagamoyo, coastal Tanzania.

OpenAIRE

Kawada, Hitoshi; Temu, Emmanuel A.; Minjas, Japhet N.; Matsumoto, Osamu; Iwasaki, Tomonori; Takagi, Masahiro

2008-01-01

Metofluthrin is a newly synthesized pyrethroid possessing high knockdown and lethal activity against mosquitoes. Studies of metofluthrin-impregnated plastic strips have been performed with dengue vectors. This study reports the efficacy of the new prototypes of metofluthrin-impregnated plastic strips against malaria vectors, Anopheles gambiae complex, in the Kongo villages of Bagamoyo district in coastal Tanzania. The study, using 20 houses, half intervention, half control, was conducted for ...

Influence of the Synthesis Method for Pt Catalysts Supported on Highly Mesoporous Carbon Xerogel and Vulcan Carbon Black on the Electro-Oxidation of Methanol

Directory of Open Access Journals (Sweden)

Cinthia Alegre

2015-03-01

Full Text Available Platinum catalysts supported on carbon xerogel and carbon black (Vulcan were synthesized with the aim of investigating the influence of the characteristics of the support on the electrochemical performance of the catalysts. Three synthesis methods were compared: an impregnation method with two different reducing agents, sodium borohydride and formic acid, and a microemulsion method, in order to study the effect of the synthesis method on the physico-chemical properties of the catalysts. X-ray diffraction and transmission electron microscopy were applied. Cyclic voltammetry and chronoamperometry were used for studying carbon monoxide and methanol oxidation. Catalysts supported on carbon xerogel presented higher catalytic activities towards CO and CH3OH oxidation than catalysts supported on Vulcan. The higher mesoporosity of carbon xerogel was responsible for the favored diffusion of reagents towards catalytic centers.

Applicability of Vacuum Impregnation to Modify Physico-Chemical, Sensory and Nutritive Characteristics of Plant Origin Products—A Review

Directory of Open Access Journals (Sweden)

Elżbieta Radziejewska-Kubzdela

2014-09-01

Full Text Available Vacuum impregnation is a non-destructive method of introducing a solution with a specific composition to the porous matrices of fruit and vegetables. Mass transfer in this process is a result of mechanically induced differences in pressure. Vacuum impregnation makes it possible to fill large volumes of intercellular spaces in tissues of fruit and vegetables, thus modifying physico-chemical properties and sensory attributes of products. This method may be used, e.g., to reduce pH and water activity of the product, change its thermal properties, improve texture, color, taste and aroma. Additionally, bioactive compounds may be introduced together with impregnating solutions, thus improving health-promoting properties of the product or facilitating production of functional food.

Adsorption of Ammonia on Regenerable Carbon Sorbents

Science.gov (United States)

Wójtowicz, Marek A.; Cosgrove, Jesph E.; Serio, Michael A..; Wilburn, Monique

2015-01-01

Results are presented on the development of reversible sorbents for the combined carbon dioxide, moisture, and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Data on sorption and desorption of ammonia, which is a major TC of concern, are presented in this paper. The current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. In this study, several carbon sorbents were fabricated and tested for ammonia sorption. Ammonia-sorption capacity was related to carbon pore structure characteristics, and the temperature of oxidative carbon-surface treatment was optimized for enhanced ammonia-sorption performance.

Studies of properties of rubber wood with impregnation of polymer

Indian Academy of Sciences (India)

Impregnation of rubber wood has been carried out under different conditions by using styrene as grafting monomer and glycidyl methacrylate (GMA) as crosslinker. Properties such as dimensional stability, water absorption, hardness, tensile strength, flexural strength, etc of the impregnated wood have been checked and ...

EFFECTS OF IMPREGNATION WITH STYRENE AND NANO-ZINC OXIDE ON FIRE-RETARDING, PHYSICAL, AND MECHANICAL PROPERTIES OF POPLAR WOOD

Directory of Open Access Journals (Sweden)

Siroos Habibzade

2016-12-01

Full Text Available Nanoparticles have been vastly applied in wood polymer composites (WPCs in the recent years to improve some of the drawbacks of solid wood species. In the present study, the effects of ZnO nanoparticles on fire retarding, physical, and mechanical properties of polymerized poplar wood were investigated. Poplar specimens were impregnated with styrene monomer, containing four different contents of nano-zinc oxide (ZnO (0, 0.5, 1 and 1.5%, based on the dry weight of monomer. Results of the scanning electron microscopy (SEM showed homogeneous dispersion of ZnO nanoparticles in the WPC matrix. Nano-zinc oxide improved physical properties such as dimensional stability and water absorption. Moreover, mechanical properties increased in comparison to the control specimens. The impregnation process also significantly improved some of the fire-retarding properties, including the ignition time; however, the flammability nature of styrene aggravated some others, such as carbonized area. It was concluded that, although most of the properties were improved, the final application of WPC should be taken in to consideration before making decision on whether or not to impregnate populus wood with styrene.

The effect of type and mixture of resin on the properties of impregnated paper

Directory of Open Access Journals (Sweden)

hossein Kermanian

2017-05-01

Full Text Available This study was carried out in order to investigate the effects of different types of resins and also their mixtures on the impregnated paper properties. In this regard, pure urea resin (100%, mixture of melamine and urea resins with various combinations (60/40 and 70/30 and 50/50, mixture of nano-fiber cellulose ratios of 1, 2 and 3 percent with urea resin and pure PVA (100% were used to impregnate of newsprint basic paper of Mazandaran wood and paper industries. Immersion of samples in the impregnation step were done in two time of 5 and 10 seconds. Next, melamine resin was used for surface coating and then absorption of resin in the impregnation and coating process measured. Results showed that in the impregnation step with pure urea (100%, in the respect of absorption rate and surface properties of melamine paper, the best time of impregnation was obtained 10 seconds. In the combined treatment, adding up to 30% melamine to urea resin, as impregnation step resin, offers better properties in terms of stain resistance, cigarette resistance, resistance to cracking and resistance to hot water steam for impregnatedmade paper. By adding nanocellulose up to 1% in impregnation resin, better properties is obtained for melamine paper. Also, PVA as impregnation resin, can be offer similar quality to pure urea in the resulting melamine papers.

Starch-modified magnetite nanoparticles for impregnation into cartilage

Energy Technology Data Exchange (ETDEWEB)

Soshnikova, Yulia M., E-mail: yuliasoshnikova@gmail.com [Russian Academy of Sciences, Institute on Laser and Information Technologies (Russian Federation); Roman, Svetlana G.; Chebotareva, Natalia A. [A.N. Bach Institute of Biochemistry (Russian Federation); Baum, Olga I. [Russian Academy of Sciences, Institute on Laser and Information Technologies (Russian Federation); Obrezkova, Mariya V. [Lomonosov Moscow State University, Department of Chemistry (Russian Federation); Gillis, Richard B.; Harding, Stephen E. [University of Nottingham, National Centre for Macromolecular Hydrodynamics (United Kingdom); Sobol, Emil N. [Russian Academy of Sciences, Institute on Laser and Information Technologies (Russian Federation); Lunin, Valeriy V. [Lomonosov Moscow State University, Department of Chemistry (Russian Federation)

2013-11-15

The paper presents preparation and characterization of starch-modified Fe{sub 3}O{sub 4} nanoparticles (NPs) in aqueous dispersion after impregnation into healthy and damaged types of cartilage. We show that starch-modified dispersion has a narrower size distribution than a non‐stabilized one. The average hydrodynamic radius of magnetite NPs in a dispersion used for impregnation into cartilage is (48 ± 1) nm with the width of the distribution from 5 to 200 nm. We investigate stability of aqueous magnetite NPs dispersions during storage and with increase in temperature (up to 70 °C). We find that polydisperse magnetite NPs can penetrate into cartilage and the size and concentration of impregnated particles depend on the organization of the tissue structure. The results confirm the possibility of application of magnetite NPs in diagnostics and laser treatment of degenerative cartilage deceases.

Resin impregnation process for producing a resin-fiber composite

Science.gov (United States)

Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

1994-01-01

Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

Electrocatalytic behavior of carbon paste electrode modified with metal phthalocyanines nanoparticles toward the hydrogen evolution

International Nuclear Information System (INIS)

Abbaspour, Abdolkarim; Norouz-sarvestani, Fatemeh; Mirahmadi, Ehsan

2012-01-01

Highlights: ► The new construction of a carbon paste electrode impregnated with nanoparticles of Zn and Ni phthalocyanine (nano ZnPc and nano NiPc). ► The decrease overpotential and higher current value obtained in nano ZnPc and nano NiPc compared to bulky ZnPc and bulky NiPc, respectively. ► Types of the catalyst and pH of the solution affect the electro catalytic proton reduction reaction considerably. - Abstract: This paper describes the construction of a carbon paste electrode (CPE) impregnated with nanoparticles of Zn and Ni phthalocyanine (nano ZnPc and nano NiPc). These new electrodes (nano ZnPc-CPE and nano NiPc-CPE) reveal interesting electrocatalytic behavior toward hydrogen evolution reaction (HER). Voltammetric characteristics indicated that the proposed electrodes display better electrocatalytic activity compared to their corresponding bulky modified metal phthalocyanines (MPcs) in minimizing overpotential and increasing the reduction current of HER. Electrocatalytic activities irregularly change with the pH of the solution. However by increasing the pH while nano MPcs are still active, bulky MPcs are almost inactive, and their corresponding ΔE increase by increasing the pH.

Carbon coated textiles for flexible energy storage

Energy Technology Data Exchange (ETDEWEB)

Jost, Kristy [Drexel Univ., Philadelphia, PA (United States). Fashion, Product, Design and Merchandising Dept., A. J. Drexel Nanotechnology Inst. and Dept. of Materials Science and Engineering; Perez, Carlos R. [Drexel Univ., Philadelphia, PA (United States). A. J. Drexel Nanotechnology Inst. and Dept. of Materials Science and Engineering; McDonough, John K. [Drexel Univ., Philadelphia, PA (United States). A. J. Drexel Nanotechnology Inst. and Dept. of Materials Science and Engineering; Presser, Volker [Drexel Univ., Philadelphia, PA (United States). A. J. Drexel Nanotechnology Inst. and Dept. of Materials Science and Engineering; Heon, Min [Drexel Univ., Philadelphia, PA (United States). A. J. Drexel Nanotechnology Inst. and Dept. of Materials Science and Engineering; Dion, Genevieve [Drexel Univ., Philadelphia, PA (United States). Fashion, Product, Design and Merchandising Dept.; Gogotsi, Yury [Drexel Univ., Philadelphia, PA (United States). A. J. Drexel Nanotechnology Inst. and Dept. of Materials Science and Engineering

2011-10-20

This paper describes a flexible and lightweight fabric supercapacitor electrode as a possible energy source in smart garments. We examined the electrochemical behavior of porous carbon materials impregnated into woven cotton and polyester fabrics using a traditional printmaking technique (screen printing). The porous structure of such fabrics makes them attractive for supercapacitor applications that need porous films for ion transfer between electrodes. We used cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy to study the capacitive behaviour of carbon materials using nontoxic aqueous electrolytes including sodium sulfate and lithium sulfate. Electrodes coated with activated carbon (YP17) and tested at ~0.25 A·g⁻¹ achieved a high gravimetric and areal capacitance, an average of 85 F·g⁻¹ on cotton lawn and polyester microfiber, both corresponding to ~0.43 F·cm⁻².

Treatment characteristics of various sediment components spiked with 2-chlorobiphenyl using reactive activated carbon.

Science.gov (United States)

Choi, Hyeok

2018-04-05

Previously, the concept of reactive activated carbon (RAC), where the porous structure of activated carbon (AC) is impregnated with palladized zerovalent iron, has been proposed to be effective to adsorb and dechlorinate polychlorinated biphenyls (PCBs). To explain the low dechlorination of PCBs bound to actual aquatic sediments under remediation with RAC, this study investigated the role of various solid organic and inorganic sediment components in adsorbing and desorbing PCBs. Detailed fate and transport mechanism of 2-chlorinated biphenyl (2-ClBP) spiked to sediment components, including kaolin, montmorillonite (MMT), coal, graphite, AC, and their mixture, was revealed. Adsorption and holding capability of sediment components toward 2-ClBP strongly influenced amount of spiked 2-ClBP, amount of desorbed 2-ClBP, overall dechlorination of 2-ClBP to biphenyl (BP), and eventual partitioning of 2-ClBP and BP to water, sediment component, and RAC. Order of the amount of spiked 2-ClBP to sediment components after drying, following AC > mixture > coal > graphite > kaolin > MMT, was in agreements (in opposite direction) with order of the amount of desorbed 2-ClBP and order of overall 2-ClBP dechlorination. Substantial role of organic components in aquatic sediments for holding 2-ClBP and thus preventing it from dechlorination on RAC was proven. Copyright © 2017 Elsevier B.V. All rights reserved.

Eucalyptus oil nanoemulsion-impregnated chitosan film: antibacterial effects against a clinical pathogen, Staphylococcus aureus, in vitro

Directory of Open Access Journals (Sweden)

Sugumar S

2015-10-01

Full Text Available Saranya Sugumar, Amitava Mukherjee, Natarajan Chandrasekaran Centre for Nanobiotechnology, VIT University, Vellore, India Abstract: Eucalyptus oil (Eucalyptus globulus nanoemulsion was formulated using low- and high-energy emulsification methods. Development of nanoemulsion was optimized for system parameters such as emulsifier type, emulsifier concentration, and emulsification methods to obtain a lower droplet size with greater stability. The minimized droplet diameter was achieved using the high-energy method of ultrasonication. Tween 80 was more effective in reducing droplet size and emulsion appearance when compared to Tween 20. Stable nanoemulsion was formulated with Tween 80 as a surfactant, and the particle size was found to be 9.4 nm (1:2 v/v. The eucalyptus oil nanoemulsion was impregnated into chitosan (1% as a biopolymer in varying concentrations. Further, the film was characterized by moisture content, microscopic study, X-ray diffraction, and Fourier transform infrared spectroscopy. Also, the film with and without nanoemulsion was evaluated against Staphylococcus aureus. The nanoemulsion-impregnated chitosan film showed higher antibacterial activity than chitosan film. These results support the inclusion of nanoemulsion-impregnated chitosan film in wound management studies. Keywords: essential oil, emulsion, biopolymer, impregnation, thin film, wound isolate

Carbon Cryogel Silicon Composite Anode Materials for Lithium Ion Batteries

Science.gov (United States)

Woodworth James; Baldwin, Richard; Bennett, William

2010-01-01

A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 10 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-4,9 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

Augmentation of tendon healing with butyric acid-impregnated sutures: biomechanical evaluation in a rabbit model.

Science.gov (United States)

Leek, Bryan T; Tasto, James P; Tibor, Lisa M; Healey, Robert M; Freemont, Anthony; Linn, Michael S; Chase, Derek E; Amiel, David

2012-08-01

Butyric acid (BA) has been shown to be angiogenic and to enhance transcriptional activity in tissue. These properties of BA have the potential to augment biological healing of a repaired tendon. To evaluate this possibility both biomechanically and histologically in an animal tendon repair model. Controlled laboratory study. A rabbit Achilles tendon healing model was used to evaluate the biomechanical strength and histological properties at 6 and 12 weeks after repair. Unilateral tendon defects were created in the middle bundle of the Achilles tendon of each rabbit, which were repaired equivalently with either Ultrabraid BA-impregnated sutures or control Ultrabraid sutures. After 6 weeks, BA-impregnated suture repairs had a significantly increased (P Tendons repaired with BA-impregnated sutures demonstrated improved biomechanical properties at 6 weeks relative to control sutures, suggesting a neoangiogenic mechanism of enhanced healing through an increased myofibroblast presence. These findings demonstrate that a relatively simple alteration of suture material may augment early tendon healing to create a stronger repair construct during this time.

Removal of Pb2+,Cd2+, Fe3+ and Sr2+ from Aqueous Solution by Selected Activated Carbons Derived from Date Pits

International Nuclear Information System (INIS)

Awwad, N.S.; Daifuallah, A.A.M.; Ali, M.M.S.

2008-01-01

Date pits (DP) as a huge solid waste in Egypt is of little or no economic value and in fact present a disposal problem. The quantity of DP has been estimated to million tons per year. DP was used for preparation of physically and chemically activated carbons. The raw materials were physically activated with pure steam, steam with flow of nitrogen gas or steam with current of air, while the chemically activated samples were prepared by impregnation of 10% ferric chloride or 10% calcium acetate. The effect of various factors, e.g., carbon type, carbon dosage, ph, initial concentration, temperature, and various inorganic ions on the adsorption capacity, were quantitatively determined. The two-parameters equilibrium models Langmuir and Freundlich equations were discussed. In this work, analyses and batch adsorption experiments have been carried out to characterize and to understand adsorption mechanism by modeling the adsorption kinetics. The present study deals with the factors affecting the uptake of Pb 2+ , Cd 2+ , Fe 3+ , and Sr 2+ ions from aqueous solution using activated carbon developed from locally available material DP, by one-step steam pyrolysis in a batch mode. Concurrently removal of these cations from aqueous medium are affected by the presence of other ions e.g. NO 3 - , CO 3 - , SO 4 - and masking agents e.g. oxalic acid and EDTA in solution. Uptake values are decreased with increasing the concentration of these ions in solution heavy metals

Influence of aging on the retention of elemental radioiodine by deep bed carbon filters under accident conditions

International Nuclear Information System (INIS)

Deuber, H.

1985-01-01

No significant difference was found in the retention of I-131 loaded as I 2 , by various impregnated activated carbons that had been aged in the containment exhaust air of a pressurized water reactor over a period of 12 months. In all the cases, the I-131 passing through deep beds of carbon was in a nonelemental form. It was concluded that a minimum retention of 99.99%, as required by new guidelines for certain accident filters, can be equally well achieved with various carbons in deep beds

In vitro adsorption study of fluoxetine in activated carbons and activated carbon fibres

Energy Technology Data Exchange (ETDEWEB)

Nabais, J.M. Valente; Mouquinho, A.; Galacho, C.; Carrott, P.J.M.; Ribeiro Carrott, M.M.L. [Centro de Quimica de Evora e Departamento de Quimica da Universidade de Evora, Rua Romao Ramalho no. 59, 7000-671 Evora (Portugal)

2008-05-15

We study the in vitro adsorption of fluoxetine hydrochloride by different adsorbents in simulated gastric and intestinal fluid, pH 1.2 and 7.5, respectively. The tested materials were two commercial activated carbons, carbomix and maxsorb MSC30, one activated carbon fibre produced in our laboratory and also three MCM-41 samples, also produced by us. Selected samples were modified by liquid phase oxidation and thermal treatment in order to change the surface chemistry without significant modifications to the porous characteristics. The fluoxetine adsorption follows the Langmuir model. The calculated Q{sub 0} values range from 54 to 1112 mg/g. A different adsorption mechanism was found for the adsorption of fluoxetine in activated carbon fibres and activated carbons. In the first case the most relevant factors are the molecular sieving effect and the dispersive interactions whereas in the activated carbons the mechanism seams to be based on the electrostatic interactions between the fluoxetine molecules and the charged carbon surface. Despite the different behaviours most of the materials tested have potential for treating potential fluoxetine intoxications. (author)

Effect of precursor and preparation method on manganese based activated carbon sorbents for removing H2S from hot coal gas.

Science.gov (United States)

Wang, Jiancheng; Qiu, Biao; Han, Lina; Feng, Gang; Hu, Yongfeng; Chang, Liping; Bao, Weiren

2012-04-30

Activated carbon (AC) supported manganese oxide sorbents were prepared by the supercritical water impregnation (SCWI) using two different precursor of Mn(NO(3))(2) (SCW(N)) and Mn(Ac)(2)·4H(2)O (SCW(A)). Their capacities of removing H(2)S from coal gas were evaluated and compared to the sorbents prepared by the pore volume impregnation (PVI) method. The structure and composition of different sorbents were characterized by XRD, SEM, TEM, XPS and XANES techniques. It is found that the precursor of active component plays the crucial role and SCW(N) sorbents show much better sulfidation performance than the SCW(A) sorbents. This is because the Mn(3)O(4) active phase of the SCW(N) sorbents are well dispersed on the AC support, while the Mn(2)SiO(4)-like species in the SCW(A) sorbent can be formed and seriously aggregated. The SCW(N) sorbents with 2.80% and 5.60% manganese are favorable for the sulfidation reaction, since the Mn species are better dispersed on the SCW(N) sorbents than those on the PV(N) sorbents and results in the better sulfidation performance of the SCW(N) sorbents. As the Mn content increases to 11.20%, the metal oxide particles on AC supports aggregate seriously, which leads to poorer sulfidation performance of the SCW(N)11.20% sorbents than that of the PV(N)11.20% sorbents. Copyright © 2012 Elsevier B.V. All rights reserved.

Preparation of supported heterogeneous catalysts by pulse impregnation: Application to Ru[sub 3](CO)[sub 12]/2,2[prime]-bipyridine/SiO[sub 2] catalyst

Energy Technology Data Exchange (ETDEWEB)

Haukka, M.; Pakkanen, T.A. (Univ. of Joensuu (Finland))

1994-07-01

In this paper, the authors introduce pulse impregnation, a method for preparing supported heterogeneous catalysts by successive impregnation cycles. Pulse impregnation is a method for preparing supported heterogeneous catalysts from the liquid phase. In the pulse-impregnation technique the catalyst surface is grown gradually in consecutive cycles, with each cycle consisting of separate deposition and activation steps. During the deposition step, the catalyst precursor or precursors are deposited onto the support from a suitable solvent. The actual chemically bonded catalyst phase is formed during the activation step (e.g., thermal activation). Pulse impregnation was tested in the separate deposition of 2,2[prime]-bipyridine and Ru[sub 3](CO)[sub 12] onto a silica support, and in the preparation of Ru[sub 3](CO)[sub 12]/2,2[prime]-bipyridine/SiO[sub 2] catalyst, in a column-type reactor system. Macroscopically uniform deposition was achieved with both 2,2[prime]-bipyridine and Ru[sub 3](CO)[sub 12]. Various solvent systems were used to control the amount of solute adsorbed during deposition. In the preparation of the Ru[sub 3](CO)[sub 12]/2,2[prime]-bipyridine/SiO[sub 2] catalyst, the ruthenium content increased nearly linearly with the number of preparation cycles. The effects of the preparation method on the catalyst activity was also tested in 1-hexane hydroformylation. 31 refs., 7 figs., 1 tab.

Effect of impregnation of ZrO2 on the chemical stability and the superconductivity of Y- and Bi-systems

International Nuclear Information System (INIS)

Muroya, Masaaki; Minamiyama, Hideaki

1994-01-01

The results are given concerning the influence of impregnation of Zr on chemical stability and superconductivity of YBa 2 (Cu 1-x · Zr x ) 3 O 7-y (123-system) and Bi 1.84 Zr x Pb 0.34 Sr 1.91 Ca 2.03 Cu 3.06 O y (2223-system) superconductors, when the samples are contacted with the solutions of acid (pH3), distilled water (pH5.6) and base (pH9), where x = 0-0.35. It is concluded that the low chemical stability was found in the case of YBZCO, barium hydroxide and/or barium carbonate were precipitated into the solutions, even though mechanical strength was increased by impregnation of Zr, and the chemical stability of Bi-system is high compared with that of the Y-system. 8 refs., 5 figs

Drug smuggling using clothing impregnated with cocaine.

Science.gov (United States)

McDermott, Seán D; Power, John D

2005-11-01

A case study is presented where a woman travelling from South America to the Republic of Ireland was detained at Dublin Airport and articles of clothing she had in her luggage were found to be impregnated with cocaine. The study shows that the amount of powder recovered from the garments was approximately 14% of the total weight of the garments. The cocaine was in the form of cocaine hydrochloride and the purity was approximately 80%. An examination of the garments under filtered light highlighted the areas exposed to cocaine and indicated that the method of impregnation was by pouring liquid containing cocaine onto the clothing.

Production of activated carbon from cellulosic fibers for environment protection

International Nuclear Information System (INIS)

Le Coq, L.; Faur, C.; Le Cloirec, P.; Phan Ngoc, H.

2005-01-01

activation with CO 2 at 950 C after a pyrolysis step using N 2 at 950 C; 2) a chemical activation where the precursors are impregnated with 30 % wt. and then activated in N 2 at 900 C. The efficiency of both activation ways are compared in terms of process mass yield, pore development (determined by N 2 adsorption at 77 K, mercury porosimetry and SEM observations) and chemical surface (elemental analysis, ash content, surface groups, pH point of zero charge). Carbonized fibers obtained by pyrolysis of jute and coconut fibers at 950 C develop a quite high porosity (BET specific surface area about 500 - 650 m 2 g -1 ) due to an oxidation process by oxygen contained in the precursors (45.7 and 42.8 wt. % for jute and coconut fibers respectively). Concerning the activation step, because of different compositions in terms of cellulose - hemi-cellulose and lignin, the activated coconut fibers present higher specific surface area (≥ 1 000 m 2 g -1 ) that activated jute fibers, with a higher micro-porosity development (about 80 % vol. against 50 %). Furthermore, for both precursors, the chemical activation by phosphoric acid seems to be 'the best' method in terms of pore development as well as acidic surface functional groups generation, due to a different activation mechanism than CO 2 . Some macro-pores are formed by the effect of oxidation gas CO 2 (Fig. 1 for jute fibers). Furthermore, these macro-pores are mainly located inside the fiber, their axis being parallel with that of the latter. The high specific surface areas, pore volumes and acidic surface groups contents developed by our fibrous activated carbons enable them to be good adsorbents for water treatment. Adsorption tests carried out in batch reactor for different industrial pollutants (phenol, a dye and a metal ion) show the importance of surface functional groups for the adsorption of all pollutants. In the case of phenol, the specific surface area bas also a major effect while it bas only an appreciated effect in

Effect of alloying on carbon formation during ethane dehydrogenation

DEFF Research Database (Denmark)

Rovik, Anne; Kegnæs, Søren; Dahl, Søren

2009-01-01

The structure sensitivity of different transition metals in the hydrogenolysis, dehydrogenation, and coking reactions during ethane conversion has been investigated. The investigated metals, Ni, Ru, Rh, and Pd, are co-impregnated with Ag onto an inactive MgAl2O4 spinel support and tested in the c......The structure sensitivity of different transition metals in the hydrogenolysis, dehydrogenation, and coking reactions during ethane conversion has been investigated. The investigated metals, Ni, Ru, Rh, and Pd, are co-impregnated with Ag onto an inactive MgAl2O4 spinel support and tested...... in the conversion of ethane. A tendency is clear for all catalysts: In the first period of time 100% ethane is converted and roughly half of the carbon is converted into coke and deposited on the catalyst. The other half of the carbon is converted into methane. The active sites in the hydrogenolysis are blocked...... by coke during the initial period where after dehydrogenation of ethane is observed. It has previously been predicted in surface science studies that Ag covers the steps of certain transition metals. Here it is documented that the hydrogenolysis and coking reactions are significantly suppressed by co...

The sampling of sulfur dioxide in air with impregnated filter paper

NARCIS (Netherlands)

Huygen, C.

1963-01-01

A method is suggested for the sampling of sulfur dioxide in air with impregnated filter paper instead of bubblers. The best aqueous impregnating solution contained potassium hydroxide with glycerol or triethanolamine. The possibilities and limitations of the method are discussed. High collection

Comparison of the Acidity of Heteropolyacids Encapsulated in or Impregnated on SBA-15

Directory of Open Access Journals (Sweden)

Pinto Teresa

2016-03-01

Full Text Available Heteropolyacids (HPA immobilized onto SBA-15 silica were prepared by two different ways using either impregnation or encapsulation methodologies. Two Keggin-type HPA, H3PW12O40 and H4SiW12O40 were considered in this study. The resulting hybrid materials were fully characterized by N2 adsorption-desorption isotherms, XRD, FT-IR, Raman, diffuse reflectance UV-Vis spectroscopies and 31P MAS NMR. All characterization methods showed that at room temperature the catalysts contained well-dispersed and intact Keggin units throughout the solid. The catalytic activity of these solids was investigated in the isomerization of n-hexane. The impregnated and encapsulated phosphotungstic catalysts performed similarly in catalysis showing that the amount of active sites was nearly the same in both catalysts. On the contrary, the tungstosilicic encapsulated material was completely inactive while its impregnated counterpart was even more active than the phosphotungstic derived catalysts. The acidity of the solids was measured by various methods: microcalorimetry of ammonia adsorption, ammonia desorption followed by Temperature Programmed Desorption (TPD and DRIFT/GC-MS and pyridine adsorption followed by infrared spectroscopy. Only pyridine adsorption and ammonia desorption followed by DRIFT/GC-MS agreed with the catalytic data. Ammonia adsorption followed by microcalorimetry was not able to differentiate between the four catalysts while the TPD experiments led to unreliable results, as not only the evolved ammonia but also other molecules such as water were taken into account in the measurements. The behavior difference between the encapsulated silico- and phosphotungstic acids was explained by a more pronounced encapsulation in the case of silicon.

Physical and chemical durability of cement impregnated epoxy resin

International Nuclear Information System (INIS)

Suryantoro

1997-01-01

Immobilization of simulation radioactive waste contains Cs and Sr with cement impregnated epoxy resin has been done. Low level liquid waste in 30% weight mixed cement homogeneously and then set in its curing time about 28 days. Waste from was impregnated with epoxy resin (Bisphenol-A-diglycidylether) and use Triethylenteramin as catalyst. the sample of cement impregnated epoxy resin 2.5 cm x 2.5 cm in diameter and length was tested by Paul Weber. The compressive strength was obtained of 4.08 kN.cm - 2. The sochxlet apparatus was run on flow rate of 300 ml/hour at 100 o C and during 24 hours. The leaching rate of Cs was round on 5.5 x 10 - 4 g.cm - 2.d - 1 and Sr was 6.1 x 10 - 4 g.cm - 2.d - 1 (author)

CO{sub 2} capture by adsorption with nitrogen enriched carbons

Energy Technology Data Exchange (ETDEWEB)

M.G. Plaza; C. Pevida; A. Arenillas; F. Rubiera; J.J. Pis [Instituto Nacional del Carbon (CSIC), Oviedo (Spain)

2007-09-15

The success of CO{sub 2} capture with solid sorbents is dependent on the development of a low cost sorbent with high CO{sub 2} selectivity and adsorption capacity. Immobilised amines are expected to offer the benefits of liquid amines in the typical absorption process, with the added advantages that solids are easy to handle and that they do not give rise to corrosion problems. In this work, different alkylamines were evaluated as a potential source of basic sites for CO{sub 2} capture, and a commercial activated carbon was used as a preliminary support in order to study the effect of the impregnation. The amine coating increased the basicity and nitrogen content of the carbon. However, it drastically reduced the microporous volume of the activated carbon, which is chiefly responsible for CO{sub 2} physisorption, thus decreasing the capacity of raw carbon at room temperature. 33 refs., 7 figs., 3 tabs.

Research and development of lithium isotope separation using an ionic-liquid impregnated organic membrane

International Nuclear Information System (INIS)

Hoshino, Tsuyoshi

2013-01-01

The tritium needed as a fuel for fusion reactors is produced by the neutron capture reaction of lithium-6 ( 6 Li) in tritium breeding materials. However, natural Li contains only about 7.6 at.% 6 Li. In Japan, new lithium isotope separation technique using ionic-liquid impregnated organic membranes have been developed. The improvement in the durability of the ionic-liquid impregnated organic membrane is one of the main issues for stable, long-term operation of electrodialysis cells while maintaining good performance. Therefore, we developed highly-durable ionic-liquid impregnated organic membrane. Both ends of the ionic-liquid impregnated organic membrane were covered by a nafion 324 overcoat to prevent the outflow of the ionic liquid. The transmission of Lithium aqueous solution after 10 hours under the highly-durable ionic-liquid impregnated organic membrane is almost 13%. So this highly-durable ionic-liquid impregnated organic membrane for long operating of electrodialysis cells has been developed through successful prevention of ion liquid dissolution. (J.P.N.)

Study of different nanostructured carbon supports for fuel cell catalysts

Science.gov (United States)

Mirabile Gattia, Daniele; Antisari, Marco Vittori; Giorgi, Leonardo; Marazzi, Renzo; Piscopiello, Emanuela; Montone, Amelia; Bellitto, Serafina; Licoccia, Silvia; Traversa, Enrico

Pt clusters were deposited by an impregnation process on three carbon supports: multi-wall carbon nanotubes (MWNT), single-wall carbon nanohorns (SWNH), and Vulcan XC-72 carbon black to investigate the effect of the carbon support structure on the possibility of reducing Pt loading on electrodes for direct methanol (DMFC) fuel cells without impairing performance. MWNT and SWNH were in-house synthesised by a DC and an AC arc discharge process between pure graphite electrodes, respectively. UV-vis spectrophotometry, scanning and transmission electron microscopy, X-ray diffraction, and cyclic voltammetry measurements were used to characterize the Pt particles deposited on the three carbon supports. A differential yield for Pt deposition, not strictly related to the surface area of the carbon support, was observed. SWNH showed the highest surface chemical activity toward Pt deposition. Pt deposited in different forms depending on the carbon support. Electrochemical characterizations showed that the Pt nanostructures deposited on MWNT are particularly efficient in the methanol oxidation reaction.

The sampling of hydrogen sulfide in air with impregnated filter paper

NARCIS (Netherlands)

Huygen, C.

1964-01-01

A method is proposed for the quantitative collection of hydrogen sulfide in air on impregnated filter paper. An aqueous solution of potassium hydroxide, potassium zincate and glycerol is used as impregnating fluid. The stability of the collected sulfide and the efficiency of collection at different

Characterization of Activated Carbons from Oil-Palm Shell by CO2 Activation with No Holding Carbonization Temperature

Directory of Open Access Journals (Sweden)

S. G. Herawan

2013-01-01

Full Text Available Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2 activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2 adsorption at 77 K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced.

Removal of phosphate from water by activated carbon fiber loaded with lanthanum oxide

International Nuclear Information System (INIS)

Zhang Ling; Wan Lihua; Chang Ning; Liu Jianyong; Duan Chao; Zhou Qi; Li Xiangling; Wang Xinze

2011-01-01

Phosphate removal from wastewater is very important for the prevention of eutrophication. Adsorption of phosphate from water was investigated using activated carbon fiber loaded with lanthanum oxide (ACF-La) as a novel adsorbent. The effects of variables (La/ACF mass ratio, impregnation time, activation time, and activation temperature) have been studied by the single-factor method. Response surface methodology (RSM), based on three-variable-three-level Box-Behnken design (BBD), was employed to assess the individual and collective effects of the main independent parameters on the phosphate removal. The optimal conditions within the range studied for preparing ACF-La were found as follows: La/ACF mass ratio of 11.78%, activation time of 2.5 h and activation temperature at 650 ° C , respectively. The phosphate removal using the ACF-La prepared under the optimal conditions was up to 97.6% even when the phosphate concentration in water was 30 mg P/L, indicating that ACF-La may be an effective adsorbent. The results from Fourier transform infrared (FT-IR) spectroscopy and change of pH values associated with the adsorption process revealed that the probable mechanism of phosphate ions onto ACF-La was not only ion exchange and coulomb interaction, but also a result of Lewis acid-base interaction due to La-O coordination bonding.

Influence of preparation conditions on porous structures of olive stone activated by H3PO4

International Nuclear Information System (INIS)

Yavuz, Reha; Akyildiz, Hanife; Karatepe, Nilguen; Cetinkaya, Eda

2010-01-01

An olive factory residue was used as a precursor in the preparation of granular activated carbon by chemical activation with H 3 PO 4 . Effects of final activation temperature, time, and H 3 PO 4 concentration used in the impregnation stage on the porous development were investigated. SO 2 adsorption experiments were also performed for some of the activated carbon samples to represent their adsorption performance. Activation at low temperature represented that micropores were developed first at early stages of the temperatures. Mesoporosity developed at around 250 C, enhanced up to 400 C, and then started to decrease due to possibly shrinking of pores. The optimum temperature for olive stone was found to be around 400 C on the basis of total pore volume and BET surface area. It was clearly demonstrated that H 3 PO 4 concentration used in the impregnation stage was not only effective for development of surface area and pore volumes but also an effective tool for tailoring the pore structure and size distribution. (author)

Production of palm kernel shell-based activated carbon by direct physical activation for carbon dioxide adsorption.

Science.gov (United States)

Rashidi, Nor Adilla; Yusup, Suzana

2018-05-09

The feasibility of biomass-based activated carbons has received a huge attention due to their excellent characteristics such as inexpensiveness, good adsorption behaviour and potential to reduce a strong dependency towards non-renewable precursors. Therefore, in this research work, eco-friendly activated carbon from palm kernel shell that has been produced from one-stage physical activation by using the Box-Behnken design of Response Surface Methodology is highlighted. The effect of three input parameters-temperature, dwell time and gas flow rate-towards product yield and carbon dioxide (CO 2 ) uptake at room temperature and atmospheric pressure are studied. Model accuracy has been evaluated through the ANOVA analysis and lack-of-fit test. Accordingly, the optimum condition in synthesising the activated carbon with adequate CO 2 adsorption capacity of 2.13 mmol/g and product yield of 25.15 wt% is found at a temperature of 850 °C, holding time of 60 min and CO 2 flow rate of 450 cm 3 /min. The synthesised activated carbon has been characterised by diverse analytical instruments including thermogravimetric analyser, scanning electron microscope, as well as N 2 adsorption-desorption isotherm. The characterisation analysis indicates that the synthesised activated carbon has higher textural characteristics and porosity, together with better thermal stability and carbon content as compared to pristine palm kernel shell. Activated carbon production via one-step activation approach is economical since its carbon yield is within the industrial target, whereas CO 2 uptake is comparable to the synthesised activated carbon from conventional dual-stage activation, commercial activated carbon and other published data from literature.

Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

Energy Technology Data Exchange (ETDEWEB)

Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

2013-01-15

The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

International Nuclear Information System (INIS)

Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C.

2013-01-01

The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

Parametric study on removal efficiency of impregnated activated charcoal and silver zeolite for radioactive methyl iodide

International Nuclear Information System (INIS)

Shiomi, H.; Yuasa, Y.; Tani, A.; Ohki, M.; Nakagawa, T.

1983-01-01

The removal efficiency of impregnated activated charcoal and silver zeolite for radioactive methyl iodide is influenced by various parameters such as temperature, relative humidity, face velocity and packing density. This study is to evaluate the dependency of the removal efficiency on each parameter and these combined parameters, quantitatively. Four types of adsorbents, BC-727, AgX, CHC-50 and SS 208C 5KI 3 , were tested. From experimental data and mass transfer theory, an experimental equation for evaluating the removal efficiency of adsorbents was derived under a series of experiments for radioactive methyl iodine-131. It was concluded that the removal efficiency calculated from the experimental equation agreed well with the experimental value. Effects of experimental specific parameters, such as Pre-flow time, methyl iodide injection time and After-flow time, on the removal efficiency of adsorbent are also described

High-Rate and Long-Term Cycle Stability of Li-S Batteries Enabled by Li2S/TiO2-Impregnated Hollow Carbon Nanofiber Cathodes.

Science.gov (United States)

Wang, Xinran; Bi, Xuanxuan; Wang, Shaona; Zhang, Yi; Du, Hao; Lu, Jun

2018-05-16

The high theoretical energy density of lithium-sulfur (Li-S) batteries makes them an alternative battery technology to lithium ion batteries. However, Li-S batteries suffer from low sulfur loading, poor charge transport, and dissolution of lithium polysulfide. In our study, we use the lithiated S, Li 2 S, as the cathode material, coupled with electrospun TiO 2 -impregnated hollow carbon nanofibers (TiO 2 -HCFs), which serve as the conductive agent and protective barrier for Li 2 S in Li-S batteries. TiO 2 -HCFs provide much improved electron/ionic conductivity and serve as a physical barrier, which prevents the dissolution of lithium polysulfides. The Li 2 S/TiO 2 -HCF composite delivers a discharge capacity of 851 mA h g Li 2 S -1 at 0.1C and the bilayer TiO 2 -HCFs/Li 2 S/TiO 2 -HCF composite delivers a high specific capacity of 400 mA h g Li 2 S -1 at 5C.

Physicochemical properties of metal-doped activated carbons and relationship with their performance in the removal of SO{sub 2} and NO

Energy Technology Data Exchange (ETDEWEB)

Gao Xiang, E-mail: xgao1@zju.edu.cn [State Key Laboratory of Clean Energy Utilization, Zhejiang University, 38 Zheda Road, Hangzhou 310027 (China); Liu Shaojun; Zhang Yang; Luo Zhongyang; Cen Kefa [State Key Laboratory of Clean Energy Utilization, Zhejiang University, 38 Zheda Road, Hangzhou 310027 (China)

2011-04-15

Research highlights: {yields} Cu and Fe were partly reduced by carbon during preparation. {yields} Metal-involved SO{sub 2} removal pathways were catalytic oxidation, reaction and adsorption. {yields} Good performances of SO{sub 2} and NO removal depended on the metal redox pairs. - Abstract: Several metal-doped activated carbons (Fe, Co, Ni, V, Mn, Cu and Ce) were prepared and characterized. The results of N{sub 2} adsorption-desorption, X-ray diffraction, and X-ray photoelectron spectroscopy indicated that some metals (Cu and Fe) were partly reduced by carbon during preparation. Activity tests for the removal of SO{sub 2} and the selective catalytic reduction of NO with ammonia were carried out. Due to different physicochemical properties, different pathways for the SO{sub 2} removal had been put out, i.e., catalytic oxidation, direct reaction and adsorption. This classification depended on the standard reduction potentials of metal redox pairs. Samples impregnated with V, Ce and Cu showed good activity for NO reduction by NH{sub 3}, which was also ascribed to the reduction potential values of metal redox pairs. Ce seemed to be a promising alternative to V due to the higher activity in NO reduction and the nontoxic property. A metal cation which could easily convert between the two valences seemed to be crucial to the good performance of both SO{sub 2} and NO removal, just like V and Cu.

Simple synthesis of mesoporous FeNi/graphitic carbon nanocomposite catalysts and study on their activities in catalytic cracking of toluene

Energy Technology Data Exchange (ETDEWEB)

Wang, Yangang, E-mail: ygwang8136@gmail.com [Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Chen, Yuting; Yao, Mingcui [Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Qin, Hengfei; Kang, Shifei; Li, Xi [Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China); Zuo, Yuanhui; Zhang, Xiaodong [Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Cui, Li-Feng, E-mail: lifeng.cui@gmail.com [Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China)

2015-11-01

Mesoporous FeNi alloy/graphitic carbon nanocomposite catalysts with different Fe/Ni molar ratios have been synthesized through a simple solid–liquid grinding/templating method using mesoporous silica SBA-15 as the template. Metal nitrates and natural soybean oil were respectively used as the magnetic particle precursors and carbon source, which can be infiltrated into the silica template after simple impregnation, grinding and subsequent heat treatment. X-ray diffraction, nitrogen adsorption–desorption, transmission electron microscopy and thermogravimetric analysis techniques were used to characterize the samples. It is observed that high contents of FeNi alloy nanoparticles with the sizes of 3–6 nm are well dispersed into the walls of graphitic mesoporous carbon matrix, and the resulting nanocomposites have a uniform mesostructure with a high specific surface area and large pore volume. Because of these properties, the obtained FeNi/graphitic carbon nanocomposites can be used as novel catalysts for the catalytic cracking of toluene and exhibit a higher activity and stability than FeNi/commercial activated carbon (AC) catalyst. After a period of 810 min reaction at 700 °C, the toluene conversion on the FeNi/graphitic carbon nanocomposites can be maintained at a level of more than 75% and this value is 2.5 times as high as that of the FeNi/AC catalyst. - Highlights: • Mesoporous FeNi alloy/graphitic carbon nanocomposites (FeNi/GCN) were synthesized. • High contents of FeNi alloy nanoparticles are well embedded into the graphitic carbon walls. • The obtained FeNi/GCN catalysts have a high surface area and uniform mesostructure. • The FeNi/GCN catalysts exhibited excellent catalytic performance in the cracking of toluene.

Processing effects in production of composite prepreg by hot melt impregnation

Science.gov (United States)

Chmielewski, C.; Jayaraman, K.; Petty, C. A.

1993-06-01

The hot melt impregnation process for producing composite prepreg has been studied. The role of the exit die is highlighted by operating without impregnation bars. Experimental results show that when a fiber tow is pulled through a resin bath and then through a wedge shaped die, the total resin mass fraction and the extent of resin impregnation in the tow increase with the processing viscosity. The penetration of resin into a fiber bundle is greater when the resin viscosity is higher. This trend is unchanged over a range of tow speeds up to the breaking point. A theoretical model is developed to describe the effect of processing conditions and die geometry on the degree of impregnation. Calculations with this model indicate that for a given die geometry, the degree of impregnation increases from 58 percent to 90 percent as the ratio of the clearance between the tow and the die wall, to the total die gap is decreased from 0.15 to 0.05. Physical arguments related to the effective viscosity of the prepreg show that the clearance ratio is independent of the tow speed, but decreases as the ratio of the effective shear viscosity of the prepreg to the resin viscosity increases. This provides a connection between the experimental results obtained with varying resin viscosity and the computational results obtained with varying clearance values at the die inlet.

Impregnation of silver sulfadiazine into bacterial cellulose for antimicrobial and biocompatible wound dressing

International Nuclear Information System (INIS)

Luan, Jiabin; Wu, Jian; Zheng, Yudong; Wang, Guojie; Guo, Jia; Ding, Xun; Song, Wenhui

2012-01-01

Silver sulfadiazine (SSD) is a useful antimicrobial agent for wound treatment. However, recent findings indicate that conventional SSD cream has several drawbacks for use in treatments. Bacterial cellulose (BC) is a promising material for wound dressing due to its outstanding properties of holding water, strength and degradability. Unfortunately, BC itself exhibits no antimicrobial activity. A combination of SSD and BC is envisaged to form a new class of wound dressing with both antimicrobial activity and biocompatibility, which has not been reported to date. To achieve antimicrobial activity, SSD particles were impregnated into BC by immersing BC into SSD suspension after ultrasonication, namely SSD–BC. Parameters influencing SSD–BC impregnation were systematically studied. Optimized conditions of sonication time for no less than 90 min and the proper pH value between 6.6 and 9.0 were suggested. The absorption of SSD onto the BC nanofibrous network was revealed by XRD and SEM analyses. The SSD–BC membranes exhibited significant antimicrobial activities against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus evaluated by the disc diffusion method. In addition, the favorable biocompatibility of SSD–BC was verified by MTT colorimetry, epidermal cell counting method and optical microscopy. The results demonstrate the potential of SSD–BC membranes as a new class of antimicrobial and biocompatible wound dressing. (paper)

Sol-gel processed thin-layer ruthenium oxide/carbon black supercapacitors: A revelation of the energy storage issues

Energy Technology Data Exchange (ETDEWEB)

Panic, V.V.; Dekanski, A.B.; Stevanovic, R.M. [Institute of Chemistry, Technology and Metallurgy, Department of Electrochemistry, University of Belgrade, Njegoseva 12, Belgrade 125213 (RS)

2010-07-01

Hydrous ruthenium oxide/carbon black nanocomposites were prepared by impregnation of the carbon blacks by differently aged inorganic RuO{sub 2} sols, i.e. of different particle size. Commercial Black Pearls 2000 {sup registered} (BP) and Vulcan {sup registered} XC-72 R (XC) carbon blacks were used. Capacitive properties of BP/RuO{sub 2} and XC/RuO{sub 2} composites were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in H{sub 2}SO{sub 4} solution. Capacitance values and capacitance distribution through the composite porous layer were found different if high- (BP) and low- (XC) surface-area carbons are used as supports. The aging time (particle size) of Ru oxide sol as well as the concentration of the oxide solid phase in the impregnating medium influenced the capacitive performance of prepared composites. While the capacitance of BP-supported oxide decreases with the aging time, the capacitive ability of XC-supported oxide is promoted with increasing oxide particle size. The increase in concentration of the oxide solid phase in the impregnating medium caused an improvement of charging/discharging characteristics due to pronounced pseudocapacitance contribution of the increasing amount of inserted oxide. The effects of these variables in the impregnation process on the energy storage capabilities of prepared nanocomposites are envisaged as a result of intrinsic way of population of the pores of carbon material by hydrous Ru oxide particle. (author)

Kinetic studies of potassium permanganate adsorption by activated carbon and its ability as ethylene oxidation material

Science.gov (United States)

Aprilliani, F.; Warsiki, E.; Iskandar, A.

2018-03-01

Generally, ethylene production in many horticultural products has been seen to be detrimental to the quality during storage and distribution process. For this reason, removing ethylene from storage or distribution atmosphere is needed to maintain the quality. One of the technologies that can be applied is the use of potassium permanganate (KMnO4). KMnO4 is an active compound that can be used as an oxidizing agent on ethylene removal process. KMnO4 is not recommended for direct used application. As the result, additional material is required to impregnate the potassium permanganate. The inert materials used are commercial activated carbon. Activated carbon is chosen because it has high surface area. The purpose of this research is to determine kinetics adsorption and oxidation model of ethylene removal material. The kinetics adsorption was determined using the pseudo-first and second-order kinetic models. The data on adsorption process show that the second-order equation is more suitable to express the adsorption process on this research. The analyzing of the ethylene oxidation capacity increased with time until it reaches an optimal value. The ethylene oxidation rate is able to be estimated by the formula r = 0.1967 [C2H4]0.99 [KMnO4]0.01; MSE = 0.44 %. The actual and estimation data of ethylene oxidation show that the model is fitted to describe the actual ethylene oxidation under same experimental conditions.

Estimation of tribological anticorrosion properties of impregnated nitriding layers

International Nuclear Information System (INIS)

Iwanow, J.; Senatorski, J.; Tacikowski, J.

1999-01-01

In this paper is described aim, experimental and test result of tribological anticorrosion properties of thin nitriding layer (12.5 μm) obtained on 45 steel grade in controlled gas-nitriding process (570 o C, 4 h) impregnated with oil-based formulations, containing corrosion inhibitor BS-43, modified with tribological additives based on ashen organometallic compounds as well as ash-free organic compounds. It was stated, that tribological additives does not influence, in fact, on behaviour of corrosion resistance of nitriding layers impregnated with oil-base formulations mainly connected with inhibitor BS-43. Synergy of tribological additive and corrosion inhibitor is however more visible in modelling of wear resistance of nitriding layer. The influence nature of tribological additives in combination with corrosion inhibitor BS-43 is dependent on their kind and as result improves or worsens the wear resistance by friction. Hence in choice of impregnated formulation, which is enable to accomplish of tribological anticorrosion requirements, determined, above all, tribological additive. (author)

Influence of preparation conditions on porous structures of olive stone activated by H{sub 3}PO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Yavuz, Reha; Akyildiz, Hanife [Istanbul Technical University, Chemical and Metallurgical Engineering Faculty, 34469 Maslak, Istanbul (Turkey); Karatepe, Nilguen; Cetinkaya, Eda [Istanbul Technical University, Institute of Energy, Renewable Energy Division, 34469 Maslak, Istanbul (Turkey)

2010-01-15

An olive factory residue was used as a precursor in the preparation of granular activated carbon by chemical activation with H{sub 3}PO{sub 4}. Effects of final activation temperature, time, and H{sub 3}PO{sub 4} concentration used in the impregnation stage on the porous development were investigated. SO{sub 2} adsorption experiments were also performed for some of the activated carbon samples to represent their adsorption performance. Activation at low temperature represented that micropores were developed first at early stages of the temperatures. Mesoporosity developed at around 250 C, enhanced up to 400 C, and then started to decrease due to possibly shrinking of pores. The optimum temperature for olive stone was found to be around 400 C on the basis of total pore volume and BET surface area. It was clearly demonstrated that H{sub 3}PO{sub 4} concentration used in the impregnation stage was not only effective for development of surface area and pore volumes but also an effective tool for tailoring the pore structure and size distribution. (author)

Electrochemical capacitive performances of nanoporous carbon derived from sunflower seed shell

Energy Technology Data Exchange (ETDEWEB)

Li, X; Xing, W.; Zhuo, S.; Zhou, J. [Shandong Univ. of Technology, Zibo (China). School of Chemical Engineering

2010-07-01

Electrochemical double-layer capacitances (EDLCs) are used in applications were high power density and long cycle life are required. Nanoporous materials are typically used to prepare EDLC electrodes due to their high surface area, good physicochemical stability, and high conductivity. In this study, nanoporous carbon materials were prepared from sunflower seed shells and used as an electrode material for an EDLC. The surface and structural properties of the carbon materials were analyzed using N{sub 2} adsorption and scanning electron microscopy (SEM) techniques. The study showed that AC-X-Y carbons prepared using the impregnation-activation process had a better capacitive behaviour and higher capacitance retention ratio at fast charge-discharge rates than carbons made using the carbonization-activation process. The improved electrochemical performance of the carbons was attributed to the abundant macroscopic pores and decreased interior micropore surface. The specific capacitances of the carbon was approximately twice that of a hard-templated mesoporous carbon in all current densities ranging from 0.25 to 10 A per g. Results indicated that sunflower seed shells can be used to prepare EDLCs. 2 refs., 1 fig.

The edible cocktail: the effect of sugar and alcohol impregnation on the crunchiness of fruit

NARCIS (Netherlands)

Scholten, E.; Peters, M.M.J.P.

2012-01-01

Vacuum impregnation is seen as a valuable technique for flavor pairing in the catering industry. One of the applications of this technique is the creation of edible cocktails by impregnating of fruits with liquors, leading to an interplay of different flavors. However, the effect of the impregnation

Preparation of very pure active carbon

International Nuclear Information System (INIS)

Sloot, H.A. van der; Hoede, D.; Zonderhuis, J.; Meijer, C.

1980-02-01

The preparation of very pure active carbon is described. Starting from polyvinylidene chloride active carbon is prepared by carbonization in a nitrogen atmosphere, grinding, sieving and activation of the powder fraction with CO 2 at 950 0 to approximately 50% burn-off. The concentrations of trace and major elements are reduced to the ppb and ppm level, respectively. In the present set-up 100 g of carbon grains and approximately 50 g of active carbon powder can be produced weekly

Carbon-Based Regenerable Sorbents for the Combined Carbon Dioxide and Ammonia Removal for the Primary Life Support System (PLSS)

Science.gov (United States)

Wojtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Manthina, Venkata; Singh, Prabhakar; Chullen, Cinda

2014-01-01

Results are presented on the development of reversible sorbents for the combined carbon dioxide and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs). Since ammonia is the most important TC to be captured, data on TC sorption presented in this paper are limited to ammonia, with results relevant to other TCs to be reported at a later time. The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Furthermore, the current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. The objective of this study was to demonstrate the feasibility of using carbon sorbents for the reversible, concurrent sorption of carbon dioxide and ammonia. Several carbon sorbents were fabricated and tested, and multiple adsorption/vacuum-regeneration cycles were demonstrated at room temperature, and also a carbon surface conditioning technique that enhances the combined carbon dioxide and ammonia sorption without impairing sorbent regeneration.

In situ treatment of concrete surfaces by organic impregnation and polymerization

International Nuclear Information System (INIS)

Ursella, P.; Moretti, G.; Pellecchia, V.

1990-01-01

The impregnation by resins of concrete structures is a process well known at PIC (Polymer Impregnated Concrete). This process improves the physical-chemical features of concrete matrixes in order to extend their durability when severe environmental conditions may occur. The main objective of this research contract has been the verification of a proper impregnation 'in situ' of existing concrete surfaces, of any laying in the space, by means of a prototype machine, expressly designed and implemented, and verification of the increase of mechanical resistance, leach resistance, durability of treated material. In a nuclear facility this goal is very important in relation to the long term integrity of concrete structures during operating lifetime and, in particular, after final shutdown. (author)

Characteristic of Polymer-Impregnated Cement Mortar: Composites: Bulk Density and Microstructure

International Nuclear Information System (INIS)

Younes, M.M.; Abo-El-Enein, S.A.; El-Saft, M.M.; Sadek, M.A.; Zohdy, K.M.

2010-01-01

The effect of radiation initiated polymerization of some monomers on the physical properties of polymer-incorporated mortar was studied. The monomers used were: castor oil (C.O.), 4, 4'-diphenylmethane diisocyanate (MDI) and methyl methacrylate (MMA). Polymerization was carried out by subjecting the monomer-impregnated mortar specimens to different doses of gamma radiation. Where polyurethane (pu) and polyurethane -methyl methacrylate copolymers were formed within the pore system. The influence of polymer impregnation on the various physico-mechanical characteristics of the resulting composites was studied with respect to bulk density and polymer loading. Scanning electron microscopy (SEM) was employed to study the micro-structural characteristics of the neat hardened Ordinary Portland Cement (OPC) mortar pastes and their polymer-impregnated composites

Impregnation of 12-tungstophosphoric acid on silica - part II: effect of different solvents on the impregnation and catalytic activity in methyl esterification of stearic acid; Impregnacao do acido 12-tungstofosforico em silica - parte II: efeito de diferentes solventes na impregnacao e atividade catalitica na esterificacao metilica de acido estearico

Energy Technology Data Exchange (ETDEWEB)

Scroccaro, Karine Isabel; Yamamoto, Carlos I., E-mail: karineisabel@yahoo.com.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Centro Politecnico. Departamento de Engenharia Quimica; Tanobe, Valcineide O. de A.; Oliveira, Alan Antonio de [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Departamento de Engenharia e Tecnologia Florestal; Wypych, Fernando [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Departamento de Quimica

2014-04-15

Materials obtained by the immobilization of 12-tungstophosphoric acid (PTA) on silica using the method of impregnation with excess solution in distinct solvents (aqueous HCl, methanol:H{sub 2}O, and acetonitrile) were evaluated for use as catalysts in the methyl esterification of stearic acid. Optimum conditions were established for the impregnation of 0.5 g (w/w) of PTA on amorphous silica, under stirring at 150 rpm for 24 h, using 20 mL of 0.1 mol L{sup -1} HCl as the solvent. After calcination at 200 deg C, high conversions were obtained under mild reaction conditions, resulting in high turnover numbers. The catalyst was evaluated in ten catalytic cycles of use, where the activity was reduced only slightly, attesting its stability and the possibility to apply it to industrial production of methylesters. (author)

Optical study of planar waveguides based on oxidized porous silicon impregnated with laser dyes

Energy Technology Data Exchange (ETDEWEB)

Chouket, A. [Unite de recherche de Spectroscopie Raman, Departement de Physique, Faculte des Sciences de Tunis, Elmanar 2092, Tunis (Tunisia); Charrier, J. [Laboratoire d' Optronique CNRS-UMR FOTON 6082, Universite de Rennes 1, ENSSAT-6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France); Elhouichet, H. [Unite de recherche de Spectroscopie Raman, Departement de Physique, Faculte des Sciences de Tunis, Elmanar 2092, Tunis (Tunisia)], E-mail: habib.elhouichet@fst.rnu.tn; Oueslati, M. [Unite de recherche de Spectroscopie Raman, Departement de Physique, Faculte des Sciences de Tunis, Elmanar 2092, Tunis (Tunisia)

2009-05-15

Oxidized porous silicon optical planar waveguides were elaborated and impregnated with rhodamine B and rhodamine 6G. The waveguiding, absorption, and photoluminescence properties of these impregnated waveguides were studied. Successful impregnation of the structure with laser dyes is shown from photoluminescence and reflectivity measurements. Furthermore, the reflectivity spectra prove the homogenous incorporation of both dye molecules inside the pores of the matrices. The refractive indices of waveguide layers were determined before and after dye impregnation to indicate the conservation of guiding conditions. The optical losses in the visible wavelengths are studied as a function of dye concentration. The dye absorption is the main reason for these losses.

Impregnation of mesoporous silica for catalyst preparation studied with differential scanning calorimetry

NARCIS (Netherlands)

Eggenhuisen, T.M.; van Steenbergen, M.J.; Talsma, H.; de Jongh, P.E.; de Jong, K.P.

2009-01-01

Aqueous impregnation of mesoporous silica as a first step in catalyst preparation was studied to investigate the distribution of the metal-precursor solution over the support. The degree of pore-filling after impregnation was determined using the freezing point depression of confined liquids. A

Different Types of Waste Melamine Impregnated Paper (MIP in Particleboard Manufacturing

Directory of Open Access Journals (Sweden)

Ibrahim Halil BASBOGA

2017-03-01

Full Text Available Two different types of waste melamine impregnated paper (WMIP were generated in the manufactured coated board product plants. First one is obtained when the neat décor papers were impregnated (in the impregnation line with melamine urea formaldehyde and other chemicals (WMIP1. The second one is generated during the coating of the melamine impregnated papers on the board surfaces (WMIP2. In this study, the utilization of both WMIPs in the production of particleboard as an adhesivereplacement was investigated. First, waste melamine impregnated papers (WMIPs granulated into flour form using Pulverizator with cooling capabilities. Then, they were dry-mixed with surface and core layer particles at 10% or 15% loadings. Three different WMIPs (WMIP1, WMIP2 or their mixtures - 70% WMIP1+30% WMIP2 were used as adhesive-replacement. Mechanical properties including bending strength, modulus of elasticity, internal bond strength and surface stability of the samples were determined according to EN 310, EN 319 and EN 317 standards, respectively. Based on the results, the type of WMIP had significant effect on all mechanical properties investigated. Particleboards produced with both 10% and 15% of WMIP1 loading provided adequate results for the related standards. The best result was obtained when 15% of WMIP1 was used. It is concluded that WMIP1 might be used as an adhesive-replacement in particleboard manufacturing and may provide economic and environmental benefits.

Processing of thermo-structural carbon-fiber reinforced carbon composites

Directory of Open Access Journals (Sweden)

Luiz Cláudio Pardini

2009-06-01

Full Text Available The present work describes the processes used to obtain thermostructural Carbon/Carbon composites. The processing of these materials begins with the definition of the architecture of the carbon fiber reinforcement, in the form of stacked plies or in the form of fabrics or multidirectional reinforcement. Incorporating fiber reinforcement into the carbon matrix, by filling the voids and interstices, leads to the densification of the material and a continuous increase in density. There are two principal processing routes for obtaining these materials: liquid phase processing and gas phase processing. In both cases, thermal processes lead to the formation of a carbon matrix with specific properties related to their precursor. These processes also differ in terms of yield. With liquid phase impregnation the yield is around 45 per cent, while gas phase processing yields around 15 per cent.

Fe{sub 2}O{sub 3}-loaded activated carbon fiber/polymer materials and their photocatalytic activity for methylene blue mineralization by combined heterogeneous-homogeneous photocatalytic processes

Energy Technology Data Exchange (ETDEWEB)

Kadirova, Zukhra C., E-mail: zuhra_kadirova@yahoo.com [Institute of General and Inorganic Chemistry, Uzbekistan Academy of Sciences, Mirzo Ulugbek Street 77a, Tashkent 100170 (Uzbekistan); Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan); Hojamberdiev, Mirabbos, E-mail: hmirabbos@hotmail.com [Department of Natural and Mathematic Sciences, Turin Polytechnic University in Tashkent, Kichik Halqa Yo’li 17, Tashkent 100095 (Uzbekistan); Katsumata, Ken-Ichi [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan); Isobe, Toshihiro [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8552 (Japan); Matsushita, Nobuhiro [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan); Nakajima, Akira [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8552 (Japan); Okada, Kiyoshi [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502 (Japan)

2017-04-30

Highlights: • Fe{sub 2}O{sub 3}-activated carbon felts was prepared for adsorption-photodegradation of dyes. • Simultaneous mineralization of MB and oxalic acid occurred under UV-irradiation. • Methylene blue adsorption was better fitted to the Langmuir model. • Increasing amount of Fe{sub 2}O{sub 3} decreased the S{sub BET} and methylene blue adsorption capacity. • Photodegraded amount of MB was increased with increasing the Fe{sub 2}O{sub 3} content. - Abstract: Fe{sub 2}O{sub 3}-supported activated carbon felts (Fe-ACFTs) were prepared by impregnating the felts consisted of activated carbon fibers (ACFs) with either polyester fibers (PS-A20) or polyethylene pulp (PE-W15) in Fe(III) nitrate solution and calcination at 250 °C for 1 h. The prepared Fe-ACFTs with 31–35 wt% Fe were characterized by N{sub 2}-adsorption, scanning electron microscopy, and X-ray diffraction. The Fe-ACFT(PS-A20) samples with 5–31 wt% Fe were microporous with specific surface areas (S{sub BET}) ranging from 750 to 150 m{sup 2}/g, whereas the Fe-ACFT(PE-W15) samples with 2–35 wt% Fe were mesoporous with S{sub BET} ranging from 830 to 320 m{sup 2}/g. The deposition of iron oxide resulted in a decrease in the S{sub BET} and methylene blue (MB) adsorption capacity while increasing the photodegradation of MB. The optimum MB degradation conditions included 0.98 mM oxalic acid, pH = 3, 0.02–0.05 mM MB, and 100 mg/L photocatalyst. The negative impact of MB desorption during the photodegradation reaction was more pronounced for mesoporous PE-W15 samples and can be neglected by adding oxalic acid in cyclic experiments. Almost complete and simultaneous mineralization of oxalate and MB was achieved by the combined heterogeneous-homogeneous photocatalytic processes. The leached Fe ions in aqueous solution [Fe{sup 3+}]{sub f} were measured after 60 min for every cycle and found to be about 2 ppm in all four successive cycles. The developed photocatalytic materials have shown good

High-surface-area active carbon

International Nuclear Information System (INIS)

O'Grady, T.M.; Wennerberg, A.N.

1986-01-01

This paper describes the preparation and properties of a unique active carbon having exceptionally high surface areas, over 2500 m 2 /gm, and extraordinary adsorptive capacities. The carbon is made by a direct chemical activation route in which petroleum coke or other carbonaceous sources are reacted with excess potassium hydroxide at 400 0 to 500 0 C to an intermediate product that is subsequently pyrolyzed at 800 0 to 900 0 C to active carbon containing potassium salts. These are removed by water washing and the carbon is dried to produce a powdered product. A granular carbon can also be made by further processing the powdered carbon by using specialized granulation techniques. Typical properties of the carbon include Iodine Numbers of 3000 to 3600, methylene blue adsorption of 650 to 750 mg/gm, pore volumes of 2.0 to 2.6 cc/gm and less than 3.0% ash. This carbon's high adsorption capacities make it uniquely suited for numerous demanding applications in the medical area, purifications, removal of toxic substances, as catalyst carriers, etc

Development of the ReuseTechnology for Radioactive Waste from Nuclear Fuel Cycle - Development of the off-gas treatment technology

International Nuclear Information System (INIS)

Oh, Won Zin; Lee, H. K.; Park, G. I.; Cho, I. H.; Choi, B. S.; Lee, K. W.; Jeong, M. S.

1998-09-01

Treatment technologies for noble gases and semi-volatile gases generated from nuclear fuel cycle process were evaluated, and the optimal process was selected based on process simplicity and safety of disposal. Evaluation of the adsorption capacity of methyl iodine on AgX(silver-impregnated zeolite) and AgS(silver-impregnated silica gel) at the temperature of 80-300 deg C was carried out, and adsorption performances of AgX and AgS were compared with that of activated carbon. CO 2 removal capacity using soda lime, activated carbon and 13X was investigated, and effect of relative humidity was identified. A preparation method of granular calcium hydroxide as a CO-2 removal sorbent using oyster-shells was characterized. This study involves the comparison of the adsorption capacities of Kr on natural or synthetic zeolites and activated carbon at high concentration and an analysis of humidity effect on water adsorption of natural-zeolite. It also was carried out that performance tests for reuse of activated carbon through desorption and re-impregnation process of TEDA/KI impregnated carbon as a removal sorbent for organic radio iodines. (author). 132 refs., 17 tabs., 29 figs

Synthesis, characterization, and application of nano hydroxyapatite and nanocomposite of hydroxyapatite with granular activated carbon for the removal of Pb2+ from aqueous solutions

International Nuclear Information System (INIS)

Fernando, M. Shanika; Silva, Rohini M. de; Silva, K.M. Nalin de

2015-01-01

Highlights: • Synthesis of neat nano Hydroxyapatite using wet chemical precipitation methods. • This resulted rod like nanocrystals with a diameter around 50–80 nm. • Impregnation of of nano HAp onto the granular activated carbon (GAC) was achieved. • Materials were characterized using FT-IR, PXRD, and SEM. • Adsorption studies were conducted for Pb 2+ ions. • The adsorption data were evaluated according to isotherm models. - Abstract: Synthesis of neat nano hydroxyapatite (HAp) was carried out using wet chemical precipitation methods at low temperature and this resulted rod like HAp nanocrystals with a diameter around 50–80 nm and length of about 250 nm. Impregnation of nano HAp onto the granular activated carbon (GAC) to prepare hydroxyapatite granular activated carbon nanocomposite (C-HAp) was carried out using in situ synthesis of nano HAp in the presence of GAC. The samples of neat nano HAp and C-HAp composite were characterized using Fourier-Transformed Infrared Spectroscopy (FT-IR), powder X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Detailed adsorption studies of neat nano HAp, C-HAp and neat GAC were conducted for Pb 2+ ions at room temperature at different pH levels. The adsorption data for Pb 2+ ions was evaluated according to both Langmuir and Freundlich adsorption isotherm models for both neat nano HAp and C-HAp separately at ambient temperature, 298 K. The equilibrium adsorption data were fitted well with Langmuir adsorption isotherm for neat nano HAp with an adsorption capacity in the range of 138–83 mg g −1 . For C-HAp nanocomposite the adsorption data were well fitted with Freundlich model and the calculated adsorption capacity was in the range of 9–14 mg g −1 . Leaching of Ca 2+ ions by neat nano HAp and C-HAp were also analyzed as a function of pH. It was found that the leaching of Ca 2+ was high in neat HAp than C-HAp. The leaching of Ca 2+ by neat HAp and C-HAp during adsorption of Pb 2+ ions were also