Activated Carbon Mass Research Articles

Effect of magnetic activated carbon on the surface hydrophobicity for initial biogranulation via response surface methodology

Biogranulation is an effective biological technology suitable for the treatment of various wastewaters. However, the major drawback of this technique is the long start-up period for biogranule development. Hence, the primary focus of this study was on cell surface hydrophobicity which is the main parameter that indicates cell agglomeration during the initial self-immobilization process of aerobic granulation. The effects of sludge concentration and magnetic activated carbon on cell surface hydrophobicity were investigated in this study. Response surface methodology (RSM) was applied to design, analyze, and optimize the outcome of the study. Experiments were performed at sludge concentration of 1,000-3,000mg/L and magnetic activated carbon mass of 1-5g/L with 24hr of aeration time. The results show that both variables yielded a positive significant effect on the initial development of aerobic granulation with 56% surface hydrophobicity. Interaction effects between variables on the responses were significant with positive estimated interaction effect at all different measured aeration time. The magnetic activated carbon acted as nuclei to induce bacterial attachment and further enhanced the initial process of biogranule development under optimal condition of 1:1.1 (sludge concentration: magnetic activated carbon). PRACTITIONER POINTS: Cell surface hydrophobicity was evaluated Magnetic activated carbon enhanced cell surface hydrophobicity Response surface methodology was employed for analyses Magnetic activate carbon mass and biomass concentration was significant Magnetic activated carbon acted as nuclei to improve biogranulation.

Experimental evaluation of porosity, axial and radial thermal conductivity, of an adsorbent material composed by mixture of activated carbon, expanded graphite and lithium chloride

In this study, an adsorbent material made up of a mixture of activated carbon, expanded graphite and lithium chloride, is proposed to evaluate its thermal properties. Ratio effect between mixing components, component particle size, and compaction pressure on porosity and thermal conductivity of composite material was experimentally evaluated. Axial and radial thermal conductivity were evaluated by ASTM C177-13 standard using the hot plate and hot wire method for the respective axial and radial conductivities. Experimental results indicate that the highest porosity reaches 0.78 and is produced with a 70% mixing ratio of activated carbon mass, 10% of LiCl mass, and 20% of expanded graphite mass. With the levels used in experimental design, axial and radial thermal conductivity obtain maximum values of 51.2 W/m K and 11.9 W/m K, respectively. After optimization process based on design of experiments for mixtures, axial and radial conductivity reach their highest values of 76.5 W/m K and 13.8 W/m K, respectively, when mixture is elaborated with a proportion of 30% activated carbon, 40% expanded graphite and 30% Lithium Chloride. This study shows that conductivity results do not vary significantly due to tests temperature.

Optimization Process of Carbon Mono Oxide (CO) Gas Emission Adsorption using Activated Carbon from Rice Husk

This study aims to investigate the optimum conditions of CO emission adsorption by activated carbon from rice husk and to select the process conditions from combination of activated carbon mass, activator concentration, and the exit gas velocity to adsorption time and CO adsorption. Rice husk was carbonized in the tube furnace at 400 °C for 1.5 hours followed chemically activated using citric acid as an activator. The activated carbon formed was further tested for its ability to adsorb CO emissions on the adsorption tube connected to the motorcycle exhaust. CO emissions from motorcycles were analysed using E-Instrument E8500 while the optimum adsorption of CO gas emission was analysed using Design Expert 6.0.8 software with Box-Behnken Design. The results concluded that variables of activated carbon mass, activator concentration, and exit gas velocity influence to the adsorption time and CO gas adsorption. Base on the optimization analysis using regression quadratic model obtained that optimum condition of the CO emission adsorption process will be achieved at 30 g of activated carbon, activator concentration (citric acid) of 0.47 M, and at a flow rate of 20 m/s. In this optimum condition, the adsorbed CO gas obtained was 55.02 ppm which occurred for 1266 seconds.

High-Voltage Aqueous Supercapacitors Based on Natfsi

Replacing the acetonitrile-based electrolyte in state-of-the-art supercapacitors by an aqueous electrolyte could make these devices environmentally more benign, improve operational safety, and render supercapacitors potentially more cost efficient. The narrow electrochemical stability window of water (~1.23 V) is the main challenge in order to increase the energy density of water based devices. Recently it was reported that ultra-highly concentrated aqueous salt solutions can provide stability windows up to 3 V1. Salt concentrations higher than 21 mol kg-1 lead to increased kinetic stability, but result in reduced ionic conductivities of typically less than 10 mS cm-1. This renders such systems unsuitable for high power applications such as supercapacitors. In a recent study, we report beneficial effects in terms of electrochemical stability and conductivity for a moderately concentrated 8m NaTFSI aqueous solution2. Following a stringent test procedure, the stability window was determined to be 1.8 V and an ionic conductivity of 48 mS cm-1 was obtained, the latter being on par with modern organic electrolytes. A 1.8 V carbon/carbon supercapacitor displayed high maximum energy density of 14.4 Wh kg-1 on the activated carbon mass level and stable cycling over 100,000 cycles. Redox active potassium iodide was added to the system in order to boost its maximum specific energy to the very high value of 37.8 Wh kg-1, which is comparable to the performance of currently available commercial acetonitrile based supercapacitors. Suo, L.; Borodin, O.; Gao, T.; Olguin, M.; Ho, J.; Fan, X.; Luo, C.; Wang, C.; Xu, K., "Water-in-salt" electrolyte enables high-voltage aqueous lithium-ion chemistries. Science 2015, 350, 938. Reber, D.; Kühnel, R.-S.; Battaglia, C., High-voltage aqueous supercapacitors based on NaTFSI. Sustainable Energy Fuels 2017, doi: 10.1039/C7SE00423K

Preliminary Studies of Activated Carbon Properties on Bagasse (Saccharum officinarum) as Adsorbent to the Purification Process of Used Cooking Oil

We characterized the activated carbon made from bagasse and then use it as an adsorbent in refining used cooking oil. The bagasse was made into carbon, then activated by treatment of temperature and immersion in 1 M H3PO4. The lowest values of the activated carbon test on the water content analysis is 3.14% and ash content is 13.61 while volatile content is 6.76% at 450C activated carbon temperature. The oil purification process is carried out with temperature variations of activated carbon and activated carbon mass as 6,8 and 1 g and then the quality of oil is analyzed on the basic of SNI 01-2901-2006 standard which includes free fatty acid and peroxide number. The lowest value of the lowest free fatty acid content is 0.3660% and peroxide number is 6.9939 meq/kg, produced at a 400C activated carbon temperature having the highest degree of crystallinity of 35.77% with 10 g of adsorbent weight.

Production of antipollutan mask based activated carbon from wasted coconut shell

Indonesia is one of the countries with the highest levels of air pollution in the world. Air pollution in Indonesia, especially in Jakarta due to the number of private vehicles increased at least 10% every year. This air pollution can have an impact on public health. One effort to do as a protection of people health is to use a mask. Activated carbon can be coated to mask in order to improve the effectiveness in reducing the pollutants. One good material used as material for activated carbon is coconut shell. Selection of coconut shell as the raw material of activated carbon is also based on cellulose content of 26.06%, hemicellulose content 27.07% and a lignin content of 29.40% in the dry state. This research was done in some variation such as activation methods, activated carbon mass, and adhesive material types. Based on pollutants adsorption test, mask with 6 grams of activated carbon, chemically activated, and used TEOS as adhesive is the best variation that able to adsorb as much 76,25% of CO2 Pollutants. Mask made in this research, has saturation time as long as 4 hours under high CO2 concentration.

Corrigendum: A Polyionic, Large‐Format Energy Storage Device Using an Aqueous Electrolyte and Thick‐Format Composite NaTi2(PO4)3/Activated Carbon Negative Electrodes

A composite anode comprising blended NASICON-structured NaTi2(PO4)3 and activated carbon has been implemented in an aqueous electrolyte electrochemical energy storage device. A simple solid-state synthetic route based on low-cost precursors was used to produce the NaTi2(PO4)3, and thick (>1 mm) freestanding electrodes were fabricated with a range of activated carbon mass fractions. Electrochemical analyses showed the efficacy and stability of this composite anode combination in a functional paradigm where both Na+ and Li+ cations can participate in the charge storage reactions. Use of this composite anode in concert with a λ-MnO2-based cathode results in an energy storage device that is low cost, robust, and of sufficient energy density to be implemented in stationary applications. Data from large-format units that contain many cells in series indicate that string-level self-balancing occurs, an effect that can be relied on for making cycle-stable high-voltage strings of cells.

A Polyionic, Large‐Format Energy Storage Device Using an Aqueous Electrolyte and Thick‐Format Composite NaTi2(PO4)3/Activated Carbon Negative Electrodes

AbstractA composite anode comprising blended NASICON‐structured NaTi2(PO4)3 and activated carbon has been implemented in an aqueous electrolyte electrochemical energy storage device. A simple solid‐state synthetic route based on low‐cost precursors was used to produce the NaTi2(PO4)3, and thick (>1 mm) freestanding electrodes were fabricated with a range of activated carbon mass fractions. Electrochemical analyses showed the efficacy and stability of this composite anode combination in a functional paradigm where both Na+ and Li+ cations can participate in the charge storage reactions. Use of this composite anode in concert with a λ‐MnO2‐based cathode results in an energy storage device that is low cost, robust, and of sufficient energy density to be implemented in stationary applications. Data from large‐format units that contain many cells in series indicate that string‐level self‐balancing occurs, an effect that can be relied on for making cycle‐stable high‐voltage strings of cells.

APLIKASI KARBON AKTIF DARI CANGKANG KELAPA SAWIT DENGAN AKTIVATOR H3PO4 UNTUK PENYERAPAN LOGAM BERAT Cd DAN Pb

This research aims to determine the optimum conditions ofactivated carbon made of palm shells activated with H3PO4as an absorber of heavy metals such as Cd and Pb. The research methodology includes the preparation of activated carbon, absorption, and testing. Absorption stage is done by varying the concentration of heavy metals are 5 ppm, 10 ppm, 15 ppm, 20 ppm and activated carbon mass per run, which is0.5 grams. Another variable are the contact time with intervals of 5 minutes and the pH arranged heavy metals 2-9. Testing activated carbon absorption to heavy metals using atomic adsorption spectrofotometric (AAS). The results showed that the most optimum absorption is concentration of 10 ppm, 40 minutes and pH absorption3-4. Absorption of heavy metals Cd and Pb obtained 84,61 % and 80,13 %.

Removal of nitric oxide and sulfur dioxide from flue gases using a FeII-ethylenediamineteraacetate solution

The combined absorption of NO and SO2 into the Fe(II)-ethylenediamineteraacetate(EDTA) solution has been realized. Activated carbon is used to catalyze the reduction of FeIII-EDTA to FeII-EDTA to maintain the ability to remove NO with the Fe-EDTA solution. The reductant is the sulfite/bisulfite ions produced by SO2 dissolved into the aqueous solution. Experiments have been performed to determine the effects of activated carbon of coconut shell, pH value, temperature of absorption and regeneration, O2 partial pressure, sulfite/bisulfite and chloride concentration on the combined elimination of NO and SO2 with FeII-EDTA solution coupled with the FeII-EDTA regeneration catalyzed by activated carbon. The experimental results indicate that NO removal efficiency increases with activated carbon mass. There is an optimum pH of 7.5 for this process. The NO removal efficiency increases with the liquid flow rate but it is not necessary to increase the liquid flow rate beyond 25 ml min−1. The NO removal efficiency decreases with the absorption temperature as the temperature is over 35 °C. The Fe2+ regeneration rate may be speeded up with temperature. The NO removal efficiency decreases with O2 partial pressure in the gas streams. The NO removal efficiency is enhanced with the sulfite/bisulfite concentration. Chloride does not affect the NO removal. Ca(OH)2 and MgO slurries have little influence on NO removal. High NO and SO2 removal efficiencies can be maintained at a high level for a long period of time with this heterogeneous catalytic process.

Pemurnian Emas dari Bijih Emas Berkadar Rendah Menggunakan Karbon Aktif dari Arang Tempurung Kelapa

The activated carbon from the coconut shell can be used as an adsorbent for the recovery of gold. The optimum condition for gold recoverywas obtained at pH 3 (for adsorption) and pH 5 (for desorption) with 1 M thyocyanate solution and a 5 cm length of column (the mass ofactivated carbon is 20 grams). In this condition, the average gold recovery is 90.00%, silver 7.28% and copper 4.93%, that were used severalgold ore samples. The average purity degree of gold is 49.67%, depend on the concentration of gold, silver and copper in the gold oresample.

Adsorption characteristics of [Fe(III)–EDTA]− on granular activated carbon from aqueous solutions

In this study, the adsorption of [Fe(III)–EDTA]− on coconut‐activated carbon from aqueous solutions has been studied in a batch stirred cell. Experiments have been carried out to investigate the effects of temperature, [Fe(III)–EDTA]− concentration, pH, and activated carbon mass on [Fe(III)–EDTA]− adsorption. The experimental results manifest that high temperature is favorable to the adsorption of [Fe(III)–EDTA]− on the activated carbon. The [Fe(III)–EDTA]− adsorption on activated carbon increases with its concentration in the aqueous solutions. However, the [Fe(III)–EDTA]− adsorption on activated carbon decreases as the pH rises. The [Fe(III)–EDTA]− adsorption on per gram of activated carbon decreases as the activated carbon mass increases. The kinetic study shows that [Fe(III)–EDTA]− adsorption on the activated carbon is in good compliance with the pseudo‐second‐order kinetic model. The Langmuir and Freundlich equilibrium isotherm models are found to provide a good fitting of the adsorption data. Thermodynamic parameters such as Ea, ΔG0, ΔH0, and ΔS0 for adsorption reaction are estimated. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 470–479, 2013

Adsorption of EDTA on activated carbon from aqueous solutions

In this study, the adsorption of EDTA on activated carbon from aqueous solutions has been investigated in a batch stirred cell. Experiments have been carried out to investigate the effects of temperature, EDTA concentration, pH, activated carbon mass and particle size on EDTA adsorption. The experimental results manifest that the EDTA adsorption rate increases with its concentration in the aqueous solutions. EDTA adsorption also increases with temperature. The EDTA removal from the solution increases as activated carbon mass increases. The Langmuir and Freundlich equilibrium isotherm models are found to provide a good fitting of the adsorption data, with R 2 = 0.9920 and 0.9982, respectively. The kinetic study shows that EDTA adsorption on the activated carbon is in good compliance with the pseudo-second-order kinetic model. The thermodynamic parameters ( E a , Δ G 0, Δ H 0, Δ S 0) obtained indicate the endothermic nature of EDTA adsorption on activated carbon.

Reduction of hexamminecobalt (III) catalyzed by coconut activated carbon

AbstractThe wet ammonia desulphurization process can be retrofitted to remove NO and SO2 simultaneously by adding soluble cobalt (II) salt into the aqueous ammonia solution. The hexamminecobalt (II), Co(NH3), is the active constituent in the removal of nitric oxide with the hexamminecobalt ammonia solution. To maintain the capability of removing NO with the hexamminecobalt solution, activated carbon is used to catalyze the reduction of hexamminecobalt (III) to hexamminecobalt (II). In this study, the study on the investigation into the intrinsic kinetics of the hexamminecobalt (III) conversion has been performed. The reduction of hexamminecobalt (III) catalyzed by coconut activated carbon has been studied in a batch stirred cell without the external or internal mass transfer resistances. The experimental results show that the reaction rate increases with the activated carbon mass and the concentration of hexamminecobalt (III). pH affects the reaction greatly. A best Co(NH3)63+ conversion is obtained at pH of 2.74. A high temperature is favorable to such reaction. The reaction is first order with respect to Co(NH3)63+. The intrinsic activation energy of 56.73 ± 1.82 kJ mol−1 has been obtained. A kinetic model for such catalytic reaction can be expressed as follow: © 2009 American Institute of Chemical Engineers Environ Prog, 2010

Modelling the solid–liquid adsorption processes using artificial neural networks trained by pseudo second order kinetics

A three-layer feed forward neural network was constructed and tested to analyze the second order kinetics of solid–liquid adsorption process. The pseudo second order kinetics of auramine O onto activated carbon was used to train the artificial neural network (ANN) to model the sorption system for various operating conditions. The operating variables studied are the contact time, initial dye concentration, agitation speed, temperature, initial solution pH and activated carbon mass. The studied operating variables were used as the input to the constructed neural network to predict the dye uptake by pseudo second order kinetics at any time as the output or the target. The dye uptake predicted by ANN trained by pseudo second order kinetics was found to be precise in representing the experimental kinetics of auramine O uptake by activated carbon. The constructed network was also found to be precise in predicting the sorption kinetics of auramine O by activated carbon for the new input data which are kept unaware of the trained neural network showing its applicability to determine the dye uptake rate for any operating conditions under interest. The ANN was also trained using pseudo second order kinetics of sorption of divalent metal ions onto peat particles and also using the second order kinetics of cadmium ions onto tree fern particles. The ANN and pseudo second order kinetics compliment each other to model the studied sorption systems for a wide range of operating conditions.

Adsorption of ammonia on activated carbon from aqueous solutions

AbstractIn this study, adsorption of ammonia on activated carbon from aqueous solutions has been studied in a batch stirred cell. Experiments have been carried out to investigate the effects of temperature, ammonia concentration, and activated carbon dose on ammonia adsorption. The experimental results manifest that the ammonia adsorption rate on activated carbon increases with its concentration in the aqueous solutions. Ammonia adsorption also increases with temperature. The ammonia removal from the solution increases as activated carbon mass increases. The Langmuir and Freundlich equilibrium isotherm models are found to provide a good fitting of the adsorption data, with r2 = 0.9749 and 0.9846, respectively. The adsorption capacity of ammonia obtained from the Langmuir equilibrium isotherm model is found to be 17.19 mg g−1. The kinetic study shows that ammonia adsorption on the activated carbon is in good compliance with the pseudo‐second‐order kinetic model. The thermodynamic parameters (▵G°, ▵H°, ▵S°) obtained indicate the endothermic nature of ammonia adsorption on activated carbon. © 2008 American Institute of Chemical Engineers Environ Prog, 2008

Neural Network Modeling and Simulation of the Solid/Liquid Activated Carbon Adsorption Process

A three-layer feed-forward neural network was constructed and tested to analyze the kinetic dye uptake of a batch activated carbon adsorption process. The operating variables studied are the contact time, initial dye concentration, agitation speed, temperature, initial solution pH, activated carbon mass, and volume of the dye solution treated. The studied operating variables were used as the input to the constructed neural network to predict the dye uptake at any time as the output or the target. The constructed network was found to be precise in modeling the rate of dye uptake for the operating conditions studied. The constructed neural network was found to be highly precise in predicting the dye uptake rate for the new input data, which are kept unaware of the trained neural network showing its applicability to determine the reaction rate for any operating conditions.

10511 非共沸混合冷媒/混合吸着材の吸脱着性能(熱工学・乱流)

Adsorption chiller that can drive with waste heat at low temperature is very important to use energy effectively. To obtain the performance of the refrigerant with the temperature of 0℃ or less, the selection of the refrigerant and the adsorbent is important. Water, methanol and mixture of them arc used as a refrigerant, and activated carbon, silica gel and mixture of them are used as an adsorbent. The influence of these mixture contents on equilibrium adsorption and adsorption rate were measured. It is clarified that the equilibrium adsorption increases as the methanol ratio and the mass fraction of activated carbon increase. Furthermore, the effect of activated carbon mass fraction on the adsorption rate was examined. The rate with the mass fraction of 50% is larger than that of 0%.

Preliminary evaluation of the cadmium concentration in seawater of the Salvador City, Brazil

A method for preconcentration and determination of trace amounts of cadmium in high saline samples is described. It is based on the adsorption of the metal in the activated carbon as complex cadmium(II)–4-(2-pyridylazo-resorcinol) (PAR). The final determination was carried by flame atomic absorption spectrometry (FAAS). The optimization of extraction parameters such as the pH effect, PAR mass, activated carbon mass and shaking time was carried out using a two-level full factorial design (2 4) and two Doehlert matrix designs. The results of the factorial design, considering the analysis of variance (ANOVA), demonstrate that all these factors are statistically significant, as well as the interactions (pH×PAR mass), (pH×activated carbon mass) and (activated carbon mass×shaking time). The final optimization was carried out using Doehlert matrix designs considering the results of the factorial design. The recoveries were quantitative (96.0–106.7%) for seawater samples spiked with Cd at concentrations of 0.125 and 0.625 μg l −1. A preconcentration factor of 149 was obtained. The effect of diverse metallic ions on the proposed procedure was investigated too. The procedure was used for cadmium determination in surface seawater samples collected in Salvador City, Brazil. The cadmium content in the analysed samples varies from 0.035 to 0.17 μg l −1. These results are agreement with other data reported in the literature.

Multivariate Optimization in Preconcentration Procedure for Manganese Determination in Seawater Samples by FAAS

In the present paper, a preconcentration procedure for manganese determination in seawater samples by flame atomic absorption spectrometry (FAAS) is proposed. It is based on the solid phase extraction of manganese(II) ions as a 4-(2-pyridylazo-resorcinol) (PAR) chelate using activated carbon as sorbent. Optimization of the experimental parameters (pH, activated carbon mass, PAR mass and shaking time) was carried out using a two-level full factorial design (24) and two Doehlert matrix designs. The results of the factorial design, considering the analysis of variance (ANOVA), demonstrate that all these factors and their interactions (pH × PAR mass; pH × activated carbon mass and activated carbon mass × shaking time) are statistically significant. Final optimization was carried out using Doehlert matrix designs considering the results of the factorial design. The validation process evaluated the following parameters: effect of other metal ions, calibration curve, precision, accuracy and robustness. The procedure allows manganese determination in seawater samples with limits of detection (3σ/S) and quantification (10σ/S) of 16 ng L−1 and 53 ng L−1 respectively, and a preconcentration factor of 152. The analysis of certified reference materials demonstrated that the proposed procedure can also be used for manganese determination in biological samples. The procedure is not affected by matrix interferences and could be satisfactorily applied in manganese determination in seawater samples. Manganese determination in surface seawater samples collected from the shore of Salvador city, Brazil, was performed, and concentrations ranging from 0.51 to 2.59 µg L−1 were found.