Impregnation Of Activated Carbon Research Articles

Разработка фильтрующе-сорбирующих материалов в целях формирования ассортимента современных фильтров для противогазов и респираторов

The article focuses on the study of filter-sorbing materials (FSM) for the development of small-sized filters and the formation of a modern filters range for gas masks and respirators. There are various kinds of filters, namely particle filters, consisting of a filter material (FM) with protection from aerosols; gas filters, consisting of coal charge with protection from various concentrations of dangerous gases and vapors and combined filters, including anti-aerosol and gas protection. But in industry, due to the improvement of working conditions at enterprises, personal respiratory protection equipment is needed both from aerosols and from low concentrations of dangerous gases and vapors in the air of the working area. The creation of a new small-sized filter with a single filter-sorbing element with low resistance to air flow during breathing is an actual task. In order to form an assortment of modern filters for gas masks and respirators, we studied FSM in the form of polymer or glass fibers sprayed with carbon particles. An experimental series of studies based on the use of FSMs with adsorbents has been carried out, activated carbon (AC) and various absorbers were obtained by impregnation of AC. It is determined that the impregnation of AC with special additives allows for additional protection from inorganic and acid gases and vapors, from ammonia. Comparative tests of the FSMs were carried out with the analysis of the research results. Optimal FSMs have been determined. The fractional composition of coal particles is determined depending on the method of their application. The sorption properties of the obtained FSMs are determined. In this work, for the first time, the combination of a filter material with AC impregnated with chemical additives in particle filters was tested and evaluated. The effect of a combination of AC and a fibrous semi-finished product on the properties of FSM has been studied.

Assessment of physical properties and antimicrobial activity of activated charcoal impregnated with silver nanoparticles against Escherichia coli

Activated charcoal possesses small pores that help in the increment of the surface area available for chemical reactions. In this study, coal samples were taken from Kalimati, Dharan, and Eastern Nepal with the goal of determining the antibacterial activity of activated charcoal against Escherichia coli. This study also measured the moisture content, volatile substances, fixed carbon, and pH of coal using proximate analysis. This study was carried out by the activated carbon impregnation with silver nanoparticles by varying with the different AgNO3 concentrations: a) 0.1 mol/liter (mol/L) b) 1 mol/L c) 1.5 mol/L one at a time. By the proximate analysis, it was found that the moisture content was 2.2%, the volatile matter was 15%, the fixed carbon was 53.8%, and the pH was 5.83. The antimicrobial activity was performed by agar well diffusion methods. With 25 mg nanoparticles the zone of inhibition against E. coli was found to be 7 mm, 8 mm and 10 mm respectively and with 50 mg nanoparticles the zone of inhibition against E. coli was found to be 9 mm, 9 mm and 12 mm with concentration 0.1 mol/L, 1 mol/L and 1.5 mol/L of AgNO3 respectively. According to Pearson correlation (r = 0.697) and a simple linear regression (R2 = 0.798), there was a positive relationship between the concentration of AgNO3 and the zone of inhibition observed against E. coli. The highest zone of inhibition (ZOI) of activated charcoal impregnation against E. coli was 12 mm at 1.5 mol/L of AgNO3 with 50 mg silver nanoparticles, which was comparatively less against seven standard antibiotics (13-29 mm ZOI).

Синтез и исследование никель-алюминиевых оксидных катализаторов на углеродном носителе

Activated carbons, which have a highly developed specific surface area and large pore sizes, have recently been increasingly considered as economically available carriers of catalytic systems for deep processing of heavy hydrocarbon feedstock. In this work, samples of catalysts obtained by impregnation of active carbon with oxides of NiO and Al2O3 were studied. It is shown that an increase in the ratio of metal cations Ni/Al in the impregnating solution from 2:1 to 3:1 leads to a decrease in the average pore diameter and an increase in the specific surface area of activated carbon by 1.5 times. Activated carbons impregnated with Ni/Al metal oxides with a ratio of metal cations in an impregnating solution of 3:1, calcined in a stream of hydrogen, have the largest pore area with a diameter of 10–200 nm. Heat treatment of Ni-Al oxide catalysts on a carbon carrier at a temperature of 450°С in a hydrogen flow leads to an increase in the pore size and a decrease in the specific surface area. Mechanical activation of oxide catalysts on a carbon carrier by ultrasonic action increases the area of the outer surface of the particles by more than two times.

Carbon Dioxide (CO2) Capture in Alkanolamines Impregnated Activated Carbon Developed from Date Stones

The concern to reduce global carbon emissions has significantly improved the development of efficient solid sorbents such as activated carbon (AC). In this study, AC is developed from date stones which is one of the abundantly found agricultural waste material in gulf region. The AC was completely characterized in terms of pore volume, surface area, stability test, volatile carbon and fixed carbon contents. Impregnation of AC was performed by three different alkanolamines, namely Diethylene triamine (DETA), Pentaethylene hexamine (PEHA) and Di-ethanol amine (DEA). The alkanolamine impregnated sorbents were utilized for CO2adsorption at temperatures of 25, 30, 40, 50, 60, 70 and 100 °C and carbon dioxide (CO2) concentrations of 10, 30, 50, 70 and 92% in helium. The adsorption phenomenon was evaluated by Langmuir isotherms for all the studied adsorbents. The AC developed from date stones provided high adsorption loading capacity of CO2 i.e., 89.79 mg/g of AC at 25 °C. Thermodynamic parameters showed that the adsorption was endothermic and spontaneous in nature. Moreover, desorption profiles reveal that DETA-AC samples provided most favorable characteristics with respect to the value of desorption constant.

A multi-stage activated carbon impregnation system: Isotherms, kinetics and multi-objective modeling optimization

A multi-stage activated carbon impregnation system, with a special emphasis on solvent reuse, is introduced and optimized in this study. Experiments and modeling optimization are combined to simultaneously minimize the solute consumption and operating time for the system. The adsorption isotherm and kinetic models are well regressed based on a series of experiments on activated carbon impregnated in triethylene tetramine solution. A multi-objective nonlinear programming optimization framework is then formulated based on the regressed isotherm and kinetic models and material balance, including activated carbon, solute, water and impurities at each stage in the system. The AUGMECON method and global solver ANTIGONE are used to solve the challenging optimization problem, and the pareto optimal solutions are obtained. Additionally, a new dimensionless number is presented to further coordinate the operating parameters for the system. The result shows that the specific solute consumption and operating time are decreased by 65.11% and 85.88%, respectively.

Preparation of Cu-Loaded Biomass-Derived Activated Carbon Catalysts for Catalytic Wet Air Oxidation of Phenol

A series of Cu-loaded biomass-derived activated carbon (Cu/AC) catalysts with various impregnation ratios were prepared by precursor impregnation (PI) and activated carbon impregnation (ACI) method...

Development of an activated carbon impregnation process with iron oxide nanoparticles by green synthesis for diclofenac adsorption.

The objective of this study was to impregnate the surface of palm coconut activated carbon with nanoparticles of iron compounds using Moringa oleifera leaf extracts and pomegranate leaf by a green synthesis method and to evaluate its adsorption capacity for sodium diclofenac. The adsorbent material was characterized by zeta potential, X-ray diffraction (XRD), N2 adsorption/desorption (BET method), transmission electronic microscopy (TEM), and scanning electronic microscopy (SEM) coupled to dispersive energy spectrometry X-ray (EDX) methods. To evaluate the adsorption capacity of sodium diclofenac, the influence of pH, kinetics, isotherms, and thermodynamic properties were analysed. The impregnated adsorbents showed efficiency in the adsorption of sodium diclofenac. The kinetic model that best fit the experimental data was the pseudo-second-order model, and the equilibrium model was the Langmuir model. As for the thermodynamic study, it was verified that the adsorption reaction for all adsorbents occurs in a spontaneous, favourable way, and it is endothermic by physisorption. Therefore, this process is promising because it is a clean and non-toxic method when compared with chemical methods for the synthesis of nanoparticles.

Activated carbon impregnation with ag and cu composed nanoparticles for escherichia coli contaminated water treatment

This study aimed to produce modified granular activated carbon (GAC) by low concentrations of silver (Ag) and/or copper (Cu) nanoparticles with antibacterial capacity for application in water purification. Modified porous materials were produced from the vacuum impregnation method, at the concentrations (mass of metal/mass of activated carbon) of Ag 8 x 10−4 g/g (Ag 0.08 %), Cu 1 x 10−2 g/g (Cu 1 %), and Ag 8 x 10−4 g/g + Cu 1 x 10−2 g/g (Ag 0.08 % Cu 1 %). The reduction of the metal salts in NPs of Ag and Cu in their metallic forms or oxides was carried out by the thermal decomposition method. The characterization of the produced porous material was performed by x‐ray diffraction, programmed temperature reduction, scanning electron microscopy, x‐ray dispersive energy spectroscopy, electron transmission microscopy, and specific surface area measurements: Brunauer, Emmet, and Teller; micropore area (t method); pore size distribution (DA method); and volume and diameter of micropores (HK method) and mesopores (BJH method). In the structure of the material produced, Ag and Cu metal compounds and AgO and CuO oxides were identified, with average crystallite sizes of < 60 nm. The efficiency of the inactivation of Escherichia coli was more significant in the GAC modified with the combination of NPs (GAC/NP‐AgCu) (6.4 log 10 units), evidencing the synergistic effect of the metals when compared to GAC/NP‐Ag (0.56 log10 units) and GAC/NP‐Cu (1.31 log10 units) modified porous material. Thus, these antibacterial materials can be used for application in water purification, improving the bacteriological quality of water intended for human consumption, noting that the low concentration of metals used can provide exceptional process efficiency.

Optimization of Fixed-Bed Design for Natural Gas Mercury Removal by Sulfur Doped into Porous Activated Carbon

The present work reports the synthesis and application of sulfur doped into porous activated carbon for removing elemental mercury from natural gas using a bench-scale fixed-bed reactor. A series of experiments were carried out to investigate the optimization of Hg0 capture. Furthermore, our experimental results about optimum conditions to remove Hg0 were 1:10 of sulfur to activated carbon impregnation ratio, 350°C of impregnation temperature, and 3 hours of impregnation time. This research showed that the prepared adsorbents were capable to remove remarkable amount of Hg0 (23.615 mg/g) at high adsorption efficiency. This study may serve as reference on natural gas power plants for the removal of Hg0 using the same conditions.

Residual Organic Compound Removal from Aqueous Solution Using Commercial Coconut Shell Activated Carbon Modified by a Mixture of Seven Metal Salts

The modified activated carbon (MAC) derived from commercial coconut shell activated carbon (AC) with mixture of seven metal salts was used as an adsorbent to remove target residual organic compound (sucrose) from aqueous solutions in batch modes. The results indicated that the highest adsorption capacity of sucrose onto MAC reached when the AC was modified at the ratio of impregnation of AC with mixture of seven metal salts, including nitrate silver (AgNO3), manganese nitrate (Mn (NO3)2), potassium bichromate (K2Cr2O7), nitrate cobalt (Co (NO3)2·6H2O), nitrate copper (Cu (NO3)2·3H2O), nitrate nickel (Ni (NO3)2·6H2O) and nitrate iron (Fe (NO3)2·9H2O) of 3% (w/w). The most appropriate conditions for sucrose adsorption onto MAC in batch experiments obtained at pH 7, contact time of 120 min, 800 mg MAC/50 mL of sucrose solution with initial concentration of 1500 mg/L. At this condition, the highest adsorption capacity of sucrose onto MAC reached 28.28 mg/g. The Langmuir, Freundlich, and Sips adsorption isothermal equilibrium models can adequately describe the adsorption properties of sucrose on MAC. The adsorption kinetic of sucrose onto MAC obeyed pseudo-first-order and pseudo-second-order models with the chemical sorption process. The saturated MAC was recovered by heat from an oven. The highest recovery efficiency of saturated MAC obtained at 180 °C in 120 min. The highest adsorption capacity of sucrose onto recovered MAC was 24.31 mg/g, appropriately adsorption capacity of initial MAC.

Preliminary Testing of Hybrid Catalytic-Plasma Reactor for Biodiesel Production Using Modified-Carbon Catalyst

Preliminary testing of hybrid catalytic-plasma reactor for biodiesel production through transesterification of soybean oil with methanol over modified-carbon catalyst was investigated. This research focused on synergetic roles of non-thermal plasma and catalysis in the transesterification process. The amount of modified-carbon catalyst with grain size of 1.75 mm was placed into fixed tubular reactor within discharge zone. The discharge zone of the hybrid catalytic-plasma reactor was defined in the volume area between high voltage and ground electrodes. Weight Hourly Space Velocity (WHSV) of 1.85 h-1 of reactant feed was studied at reaction temperature of 65 oC and at ambient pressure. The modified-carbon catalyst was prepared by impregnation of active carbon within H2SO4 solution followed by drying at 100 oC for overnight and calcining at 300 oC for 3 h. It was found that biodiesel yield obtained using the hybrid catalytic-plasma reactor was 92.39% and 73.91% when using active carbon and modified-carbon catalysts, respectively better than without plasma. Therefore, there were synergetic effects of non-thermal plasma and catalysis roles for driving the transesterification process.

Enhancement of Efficiency of Activated Carbon Impregnated Chitosan for Carbon Dioxide Adsorption

The effect of carbon dioxide (CO2) on global warming is serious problem. The adsorption with solid sorbents is one of the most appropriate options. In this study, the most interesting adsorbent is granular activated carbon (GAC). It is suitable material for CO2 adsorption because of its simple availability, many specific surface area, and low-cost material. Afterwards, GAC was impregnated with chitosan solution as impregnated granular activated carbon (CGAC) in order to improve the adsorption capacity of GAC. This research aims to compare the physical and chemical characteristics of GAC and CGAC. The experiment was carried out to evaluate the efficiency of CO2 adsorption between GAC and CGAC. The results indicated that the iodine number of GAC and CGAC was 137.17 and 120.30 mg/g, respectively. The Brunauer-Emmett-Teller results (BET) of both GAC and CGAC show that specific surface area was 301.9 and 531.3 m 2 /g, respectively; total pore volume was 0.16 and 0.29 cm 3 /g, respectively; and mean diameter of pore was 2.18 and 2.15 nm, respectively. Finally, the CO2 adsorption results of both GAC and CGAC in single column how the maximum adsorption capacity was 0.17 and 0.25 mol/kg, respectively; how degeneration time was 49.6 and 80.0 min, respectively; and how the highest efficiency of CO2 adsorption was 91.92% and 91.19%, respectively.

Phosgene toxic effects and influence of a new impregnant on protection

Phosgene is a gas which affects the respiratory organs, causes pulmonary edema and suffocation. For the protection, activated carbon based filters are used. The filters are universal and used for a big number of pollutants. The objective of this study was to determine a new impregnant which would provide the respiratory protective filter with a greater adsorption capacity and longer service life. The activated carbon impregnation was performed with sodium and the filters were tested on a dynamic- sorption apparatus. The study results show that the optimal amount of sodium over activated carbon is 1.3 mal/dm³ and this amount of sodium provides the filter with the sorption capacity of 16.96 g and service life of 1532 s. Adsorbed water also has an effect on both the sorption capacity and service life of the filter. The study shows that the optimal amount of the adsorbed water in the filter activated carbon is 23% and it increases the filter sorption capacity by 18.49% and the service life up to 1674 s.

Removal of Odor Originating from Kitchen Wastewater Treatment Facilities by Activated Carbon Impregnated Iodic Acid

Removal of Odor Originating from Kitchen Wastewater Treatment Facilities by Activated Carbon Impregnated Iodic Acid

SO 2 retention on CaO/activated carbon sorbents. Part II: Effect of the activated carbon support

The present paper analyses the role of the activated carbon (AC) properties on the SO 2 uptake capacity of CaO/AC sorbents prepared by AC impregnation or ionic exchange with calcium acetate water solutions. Gas adsorption and mercury porosimetry have been used for textural characterization of the AC and surface oxygen groups have been characterized by temperature programmed desorption (TPD). Thermogravimetry has been used for SO 2 retention tests and CO 2 chemisorption at 300 °C for CaO dispersion (d) determinations. The results show that the surface calcium on CaO/AC samples, determined as “Ca loading · CaO dispersion” (parameter Ca(%) · d), governs the SO 2 uptake. The surface oxygen content is the AC property that mainly controls both the calcium loading and surface calcium on CaO/AC samples, which could be explained by the fact that the surface oxygen lowers the hydrophobic character of the AC supports therefore favouring the interaction with the calcium acetate water solutions. The combination of high calcium loading and dispersion leads to SO 2 uptakes up to 123 mg SO 2/g. The textural properties of the supports have some influence in the calcium loading. However, the effect is masked by the blockage of AC porosity by the calcium loaded.

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

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.

Selective Dimerization of Ethene over Lanthanide Catalysts Deposited from Eu or Yb Metal Solutions in Liquid Ammonia

Abstract Europium and ytterbium catalysts obtained by impregnation of active carbon with lanthanide metal (Eu and Yb) solutions in liquid ammonia were found to be active for the dimerization of ethene. Ethene was selectively dimerized at 423–473 K to yield butene isomers with selectivity of 10–62%. The active catalysts were characterized as lanthanide nitride formed by the thermal decomposition of its amide.

Study on Active Carbon-Supported Two-Component Catalysts for NO Conversion

The impregnation of active carbon with two-component aqueous solutions of Cu and Co nitrates has been investigated and different deposition degrees of copper and cobalt ions have been established. Adsorption analysis has shown modification of the active carbon texture after impregnation with solutions whose concentration of Cu and Co ions exceeds 3%. A catalyst with a high activity in the reduction of NO with CO at 100°C has been obtained. All samples are found to catalyze the complete reduction of NO to N2. A correlation between the catalytic activity and the Cu:Co ratio in the supported phase has been established.

Catalytic properties of lanthanide amide, imide and nitride formed by thermal degradation of liquid ammonia solutions of Eu and Yb metal

The catalytic properties of lanthanide amide, imide and nitride prepared by the use of liquid ammonia solutions of lanthanide metals (Ln=Eu and Yb) were studied for catalytic hydrogenation. The reaction of Eu or Yb metal solutions in liquid ammonia with silica yielded SiO2-grafted lanthanide amide in the divalent state. The divalent amide showed catalytic activity for the selective hydrogenation of dienes and benzene. It was found that partial hydrogenation of benzene occurred with a very high selectivity for cyclohexene. Amides of calcium, strontium and barium were examined similarly in connection with catalytic studies on divalent amides. Imide and nitride, into which the lanthanide (Ln/AC) deposited by impregnation of active carbon (AC) with liquid ammonia solutions of lanthanide metals were converted thermally, were studied catalytically. It was concluded that imide or imide-like species generated during the thermal degradation of lanthanide amide to nitride were very active in the hydrogenation of ethene. Lanthanide nitride was virtually inactive, but the nitride highly dispersed on active carbon was activated when subjected to evacuation treatment above about 1000K.

Reactivities and Properties of Lanthanide Catalysts Prepared by Thermal Degradation of Liquid Ammonia Solutions of Eu or Yb Metal

Abstract Studies of X-ray diffraction, Fourier-transform infrared spectra and catalytic properties of lanthanide catalysts (Eu/AC and Yb/AC) prepared by impregnation of active carbon (AC) with liquid ammonia solutions of Eu or Yb metal were carried out for the catalytic hydrogenation of ethene. The lanthanides thus deposited on AC were changed through varied steps (metal, amide, imide or nitride) by thermal treatments and simultaneously the hydrogenation activity varied markedly. Eu/AC and Yb/AC which were subjected to the evacuation treatment around 573 and 773 K, respectively, showed a high activity even at 203 K. The catalytic properties of lanthanide amide (Eu(NH2)2, Yb(NH2)2, and Yb(NH2)3) prepared separately, imide and nitride were investigated for comparison. It was concluded that imide or imide-like species formed during the thermal decomposition processes of europium(II) and ytterbium(II and III) amides to nitride at 503—573 and 423—773 K was active catalysts for Eu/AC and Yb/AC, respectively.