Assessment of alternate characterization tests for prediction of taste and odour control by granular activated carbon

2012 ◽  
Vol 12 (4) ◽  
pp. 531-539 ◽  
Author(s):  
Kyla Smith ◽  
Xiaodan Zhang ◽  
Ron Hofmann
Keyword(s):  
Activated Carbon ◽  
Natural Waters ◽  
Activated Carbons ◽  
High Energy ◽  
Bet Surface Area ◽  
Small Scale ◽  
Adsorption Sites ◽  
Surface Areas ◽  
Odour Control ◽  
American Society

The acetoxime number test was recently identified by the American Society for Testing and Materials as a method to characterize activated carbon. This adsorption isotherm gives information about the number of high energy adsorption sites on the surface of an activated carbon. A similar test uses tetrafluoromethane for the same purpose. In contrast, the more common iodine number and Brunauer, Emmet and Teller (BET) surface area parameters are a measure of the total number of adsorption sites. 2-Methylisoborneol (MIB) is reported to require high energy sites for removal, so it was hypothesized that data from acetoxime and tetrafluoromethane isotherm tests for different activated carbons would be better correlated to MIB removal than iodine numbers or BET surface areas. MIB breakthrough was monitored in rapid small-scale column tests (RSSCTs) using four natural waters and five activated carbons. Results showed no correlation between acetoxime or tetrafluoromethane isotherms and MIB breakthrough.

scholarly journals 1.8 V Aqueous Symmetric Carbon-Based Supercapacitors with Agarose-Bound Activated Carbons in an Acidic Electrolyte

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1731
Author(s):  
Chih-Chung Lai ◽  
Feng-Hao Hsu ◽  
Su-Yang Hsu ◽  
Ming-Jay Deng ◽  
Kueih-Tzu Lu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Sulfuric Acid ◽  
Energy Density ◽  
Activated Carbons ◽  
High Energy ◽  
Aqueous Electrolytes ◽  
Alternative Material ◽  
Aqueous Cells ◽  
Acidic Electrolyte ◽  
Cycling Behavior

The specific energy of an aqueous carbon supercapacitor is generally small, resulting mainly from a narrow potential window of aqueous electrolytes. Here, we introduced agarose, an ecologically compatible polymer, as a novel binder to fabricate an activated carbon supercapacitor, enabling a wider potential window attributed to a high overpotential of the hydrogen-evolution reaction (HER) of agarose-bound activated carbons in sulfuric acid. Assembled symmetric aqueous cells can be galvanostatically cycled up to 1.8 V, attaining an enhanced energy density of 13.5 W h/kg (9.5 µW h/cm2) at 450 W/kg (315 µW/cm2). Furthermore, a great cycling behavior was obtained, with a 94.2% retention of capacitance after 10,000 cycles at 2 A/g. This work might guide the design of an alternative material for high-energy aqueous supercapacitors.

scholarly journals Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review

2012 ◽  
Vol 1 (3) ◽  
pp. 75 ◽  
Author(s):  
W.D.P Rengga ◽  
M. Sudibandriyo ◽  
M Nasikin
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Chemical Activation ◽  
High Energy ◽  
Hydrogen Gas ◽  
Agricultural Product ◽  
Adsorption Method ◽  
Modified Activated Carbon ◽  
Nano Size ◽  
Formaldehyde Adsorption

Gas storage is a technology developed with an adsorptive storage method, in which gases are stored as adsorbed components on the certain adsorbent. Formaldehyde is one of the major indoor gaseous pollutants. Depending on its concentration, formaldehyde may cause minor disorder symptoms to a serious injury. Some of the successful applications of technology for the removal of formaldehyde have been reported. However, this paper presents an overview of several studies on the elimination of formaldehyde that has been done by adsorption method because of its simplicity. The adsorption method does not require high energy and the adsorbent used can be obtained from inexpensive materials. Most researchers used activated carbon as an adsorbent for removal of formaldehyde because of its high adsorption capacity. Activated carbons can be produced from many materials such as coals, woods, or agricultural waste. Some of them were prepared by specific activation methods to improve the surface area. Some researchers also used modified activated carbon by adding specific additive to improve its performance in attracting formaldehyde molecules. Proposed modification methods on activation and additive impregnated carbon are thus discussed in this paper for future development and improvement of formaldehyde adsorption on activated carbon. Specifically, a waste agricultural product is chosen for activated carbon raw material because it is renewable and gives an added value to the materials. The study indicates that the performance of the adsorption of formaldehyde might be improved by using modified activated carbon. Bamboo seems to be the most appropriate raw materials to produce activated carbon combined with applying chemical activation method and addition of metal oxidative catalysts such as Cu or Ag in nano size particles. Bamboo activated carbon can be developed in addition to the capture of formaldehyde as well as the storage of adsorptive hydrogen gas that supports renewable energy. Keywords: adsorption; bamboo; formaldehyde; modified activated carbon; nano size particles

scholarly journals Sustainable Conversion of Agriculture and Food Waste into Activated Carbons Devoted to Fluoride Removal from Drinking Water in Senegal

2015 ◽  
Vol 8 (1) ◽  
pp. 8 ◽  
Author(s):  
Mohamad M. Diémé ◽  
Maxime Hervy ◽  
Saïdou N. Diop ◽  
Claire Gérente ◽  
Audrey Villot ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Public Health Problem ◽  
Calcium Content ◽  
Fluoride Removal ◽  
Carbonaceous Materials ◽  
Water Steam ◽  
Surface Areas ◽  
Fluoride Adsorption

<p>The objective of this study was to investigate the production of activated carbons (AC) from cashew shells, and millet stalks and their efficiency in fluoride retention. These agricultural residues are collected from Senegal. It is known that some regions of Sénégal, commonly called the groundnut basin, are affected by a public health problem caused by an excess of fluoride in drinking water used by these populations. The activated carbons were produced by a combined pyrolysis and activation with water steam; no other chemical compounds were added. Then, activated carbonaceous materials obtained from cashew shells and millet stalks were called CS-H<sub>2</sub>O and MS-H<sub>2</sub>O respectively. CS-H<sub>2</sub>O and MS-H<sub>2</sub>O show very good adsorbent features, and present carbon content ranges between 71 % and 86 %. The BET surface areas are 942 m² g<sup>-1</sup> and 1234 m².g<sup>-1</sup> for CS-H<sub>2</sub>O and MS-H<sub>2</sub>O respectively. A third activated carbon produced from food wastes and coagulation-flocculation sludge (FW/CFS-H<sub>2</sub>O) was produced in the same conditions. Carbon and calcium content of FW/CFS-H<sub>2</sub>O are 32.6 and 39.3 % respectively. The kinetics sorption were performed with all these activated carbons, then the pseudo-first equation was used to describe the kinetics sorption. Fluoride adsorption isotherms were performed with synthetic and natural water with the best activated carbon from kinetics sorption, Langmuir and Freundlich models were used to describe the experimental data. The results showed that carbonaceous materials obtained from CS-H<sub>2</sub>O and MS-H<sub>2</sub>O were weakly efficient for fluoride removal. With FW/CFS-H<sub>2</sub>O, the adsorption capacity is 28.48 mg.g<sup>-1 </sup>with r² = 0.99 with synthetic water.</p>

scholarly journals Impact of reaction vessel pressure on the synthesis of sliced activated carbon from date palm tree fronds

2015 ◽  
Vol 69 (5) ◽  
pp. 561-565 ◽  
Author(s):  
Muhammad Shoaib ◽  
Hassan Al-Swaidan
Keyword(s):  
Electron Microscopy ◽  
Flow Rate ◽  
Activated Carbons ◽  
Single Step ◽  
Reaction Vessel ◽  
Bet Surface Area ◽  
Palm Tree ◽  
Surface Areas ◽  
Transmission Electron ◽  
Co2 Flow

The effects of the reaction vessel pressure on the BET surface area, pore volume and pore size of the synthesis of sliced activated carbons (SAC) at 850?C starting from 0.10 to 0.40 bars were investigated. Other synthetic variables like dwell time, CO2 flow rate and heating ramp rate were kept constant during the whole study. Methodology involves a single step procedure using the mixture of gases (N2 and CO2). During activation flow rate of both gases are kept at 150 and 50ml/min respectively. The BET surface areas of the SAC prepared at 0.10, 0.15, 0.20, 0.25, 0.30, 0.35 and 0.40 bar after 30 minutes activation time are 666, 745, 895, 1094, 835, 658 and 625 m2/g, respectively. Scanning electron microscopy (SEM) for surface morphology, Energy dispersive spectroscopy (EDS), Transmission electron microscopy (TEM) for nano particle size were also carried out that also confirms the same trend.

scholarly journals Possibility of Removing Phosphates from Activated Charbon Made from Date Kernels

2021 ◽  
Vol 06 (03) ◽  
Author(s):  
Nora Seghairi ◽  
Keyword(s):  
Activated Carbon ◽  
Natural Waters ◽  
Activated Carbons ◽  
Kinetic Studies ◽  
Phosphate Adsorption ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Isotherm Study ◽  
Freundlich Isotherms ◽  
Batch Tests

Phosphates in natural waters and whatever their origin, promote the formation of algae, reduce dissolved oxygen and reduce biodiversity in aquatic ecosystems. At high doses, phosphate salts can cause health problems. The objective of our study was to develop a simple, efficient and environmentally friendly sorption depollution technique on available and inexpensive media. We have studied the adsorption of phosphate on activated carbons prepared from date kernels. Batch tests were carried out in order to study different operating parameters such as the effect of contact time, pH, initial phosphate concentration and adsorbent dosage and adsorption kinetic. The sorption equilibrium was analyzed by Langmuir, Freundlich isotherms model. Results show that the phosphate adsorption was reversible and the quantity adsorbed reached its maximum value (14.49 mg/g) after 40 minutes. It was also found that phosphate uptake was affected by variation of pH, initial concentration of phosphate and activated carbon dosage. The adsorption improved with an acidic pH (pH = 6), initial concentration and adsorbent dosage. The results of kinetic studies revealed that adsorption phosphate on activated carbon based on date kernels (Biocar) and the intra-particle diffusion involved in the adsorption mechanism. Also, isotherm study showed that Langmuir isotherm best fit the data and the adsorption was a physical type.

scholarly journals Waste biomass as sources for activated carbon production-A review

2013 ◽  
Vol 47 (4) ◽  
pp. 347-364 ◽  
Author(s):  
MS Islam ◽  
MA Rouf
Keyword(s):  
Activated Carbon ◽  
Process Parameters ◽  
Activated Carbons ◽  
Low Cost ◽  
Process Conditions ◽  
Waste Biomass ◽  
Active Carbons ◽  
Carbon Production ◽  
Surface Areas ◽  
Physical And Chemical

A review of the production of activated carbons from waste biomass has been presented. The effects of various process parameters on the pyrolysis stage have been reviewed. Influences of activating conditions, physical and chemical, on the active carbon properties have been discussed. Under certain process conditions several active carbons with BET surface areas, ranging between 250 and 2410 m2/g and pore volumes of 0.022 and 91.4 cm3/g, have been produced. A comparison in characteristics and uses of activated carbons from waste biomass with those of commercial carbons has been made. Waste biomass being highly efficient, low cost and renewable sources of activated carbon production. Bangladesh J. Sci. Ind. Res. 47(4), 347-364, 2012 DOI: http://dx.doi.org/10.3329/bjsir.v47i4.14064

Adsorption of Soluble Metal Ions from Red Mud by Modified Activated Carbon

2008 ◽  
Vol 368-372 ◽  
pp. 1541-1544 ◽  
Author(s):  
Hua Lei Zhou ◽  
Dong Yan Li ◽  
Guo Zhuo Gong ◽  
Ya Jun Tian ◽  
Yun Fa Chen
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Red Mud ◽  
Activated Carbons ◽  
Valuable Metal ◽  
Surface Areas ◽  
Alumina Industry ◽  
Modified Activated Carbons ◽  
Almost All

Activated carbon was employed as the adsorption carrier for the metal ions in HCl solution of red mud, a solid waste produced in alumina industry. To improve the adsorption capacity to valuable metal ions, the activated carbon was modified by chemicals including HNO3, H2O2, H2SO4, H3PO4, NH3, Na2CO3, and tri-butyl phosphate (TBP). It was found that the modifications contributed the high adsorption capacity to almost all metal ions we focused on. In the case of TBP, remarkably higher adsorption capacity and selectivity of Sc3+ was observed. The correlation between the surface areas, IR spectra of those chemically modified activated carbons and adsorption was schemed.

scholarly journals Phenol adsorption on high microporous activated carbons prepared from oily sludge: equilibrium, kinetic and thermodynamic studies

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
N. Mojoudi ◽  
N. Mirghaffari ◽  
M. Soleimani ◽  
H. Shariatmadari ◽  
C. Belver ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Pore Volume ◽  
Activated Carbons ◽  
Ph Value ◽  
Chemical Activation ◽  
Bet Surface Area ◽  
Polluted Water ◽  
Oily Sludge ◽  
Maximum Adsorption Capacity ◽  
Adsorption Desorption

AbstractThe purpose of this study was the preparation, characterization and application of high-performance activated carbons (ACs) derived from oily sludge through chemical activation by KOH. The produced ACs were characterized using iodine number, N2 adsorption-desorption, Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The activated carbon prepared under optimum conditions showed a predominantly microporous structure with a BET surface area of 2263 m2 g−1, a total pore volume of 1.37 cm3 g−1 and a micro pore volume of 1.004 cm3 g−1. The kinetics and equilibrium adsorption data of phenol fitted well to the pseudo second order model (R2 = 0.99) and Freundlich isotherm (R2 = 0.99), respectively. The maximum adsorption capacity based on the Langmuir model (434 mg g−1) with a relatively fast adsorption rate (equilibrium time of 30 min) was achieved under an optimum pH value of 6.0. Thermodynamic parameters were negative and showed that adsorption of phenol onto the activated carbon was feasible, spontaneous and exothermic. Desorption of phenol from the adsorbent using 0.1 M NaOH was about 87.8% in the first adsorption/desorption cycle and did not decrease significantly after three cycles. Overall, the synthesized activated carbon from oily sludge could be a promising adsorbent for the removal of phenol from polluted water.

scholarly journals Specific adsorption sites and conditions derived by thermal decomposition of activated carbons and adsorbed carbamazepine

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel Dittmann ◽  
Paul Eisentraut ◽  
Caroline Goedecke ◽  
Yosri Wiesner ◽  
Martin Jekel ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Evolved Gas Analysis ◽  
Gas Analysis ◽  
Specific Adsorption ◽  
Adsorption Mechanisms ◽  
Adsorption Sites ◽  
Adsorption Processes ◽  
Inorganic Constituents

AbstractThe adsorption of organic micropollutants onto activated carbon is a favourable solution for the treatment of drinking water and wastewater. However, these adsorption processes are not sufficiently understood to allow for the appropriate prediction of removal processes. In this study, thermogravimetric analysis, alongside evolved gas analysis, is proposed for the characterisation of micropollutants adsorbed on activated carbon. Varying amounts of carbamazepine were adsorbed onto three different activated carbons, which were subsequently dried, and their thermal decomposition mechanisms examined. The discovery of 55 different pyrolysis products allowed differentiations to be made between specific adsorption sites and conditions. However, the same adsorption mechanisms were found for all samples, which were enhanced by inorganic constituents and oxygen containing surface groups. Furthermore, increasing the loadings led to the evolution of more hydrated decomposition products, whilst parts of the carbamazepine molecules were also integrated into the carbon structure. It was also found that the chemical composition, especially the degree of dehydration of the activated carbon, plays an important role in the adsorption of carbamazepine. Hence, it is thought that the adsorption sites may have a higher adsorption energy for specific adsorbates, when the activated carbon can then potentially increase its degree of graphitisation.

Activated Carbons for Ventilation Air Methane Enrichment by Vacuum Pressure Swing Adsorption

2013 ◽  
Vol 773 ◽  
pp. 907-911
Author(s):  
Shao Bo Ouyang ◽  
Shao Ping Xu ◽  
Ning Song
Keyword(s):  
Activated Carbon ◽  
Flow Rate ◽  
Gas Turbines ◽  
Pressure Swing Adsorption ◽  
Methane Concentration ◽  
Activated Carbons ◽  
Vacuum Pressure ◽  
Bet Surface Area ◽  
Vacuum Pressure Swing Adsorption ◽  
Pressure Swing

A coconut shell based activated carbon with BET surface area of 795 m2/g, micropore volume 0.37 mL/g and total pore volume 0.44 mL/g was prepared. With this activated carbon as adsorbent, the ventilation air methane (VAM) enrichment by vacuum pressure swing adsorption (VPSA) was investigated. The influence of VPSA parameters such as feed flow rate, effluent flow rate and adsorption time on the performance of the VAM enrichment were examined. The results showed the methane concentration in the simulative VA gas could be enriched by VPSA from 0.52 vol.% to 1.51 vol.% with a methane recovery of 96.3 % at 25 °C and 200 kPa. The methane concentration in effluent gas was reduced to below 200 ppm. The as-prepared activated carbon could be used in the VAM enrichment by VPSA for lean-burn gas turbines.

Sign in / Sign up

Export Citation Format

Share Document