Prediction of Chlorophenols Adsorption on Activated Carbons By Representative Pores Method

2021 ◽  
Author(s):  
José Carlos Alexandre de Oliveira ◽  
Paulo Ricardo Moura Rodrigues ◽  
Sebastião Mardonio Pereira de Lucena
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Experimental Tests ◽  
Quantitative Prediction ◽  
Carbon Adsorbents ◽  
Phenol Adsorption ◽  
Carbon Adsorption ◽  
New Information ◽  
Low Concentrations ◽  
Dilute Aqueous Solutions

Abstract The specification of a particular activated carbon adsorbents for removal of phenol and related derivatives, from dilute aqueous solutions, is still based on lengthy trial and error experimental tests. A predictive model of adsorption of these compounds would considerably reduce the carbon selection time and could also bring new information to support more efficient carbon synthesis. The use of molecular simulation and the methodology of representative pores, proved to be adequate for quantitative prediction of phenol adsorption. Here the methodology is being extended to chlorophenols, an important class of phenol-derived pollutants. A set of ortho and para-chlorophenol isotherms were simulated for different representative pores in order to predict carbon adsorption and determine the most significative pore size. At low concentrations (1x10-4 mol/L), the pores of 8.9 and 18.5 Å are the most effective. For concentrations above 3 x10-4 mol/L pores in the range of 27.9 Å must be present in the activated carbon. The adsorption isotherm difference between ortho and para-chlorophenol, identified experimentally, was reproduced in the simulation and its origin was investigated further. Finally, the adsorption isotherms of chlorophenols for other activated carbons were predicted with the help of the model.

scholarly journals Removal of Selected Dyes on Activated Carbons

2021 ◽  
Vol 13 (8) ◽  
pp. 4300
Author(s):  
Ewa Okoniewska
Keyword(s):  
Activated Carbon ◽  
High Efficiency ◽  
Activated Carbons ◽  
Oxygen Demand ◽  
Activated Carbon Adsorption ◽  
Metal Compounds ◽  
Carbon Adsorption ◽  
Low Concentrations ◽  
Wide Range ◽  
Living Organisms

Dyes are widely used in various industries such as those involving paper, food, plastics, and fibers. The produced wastewater has a specific character. Organic substances found in wastewater and when introduced into natural water bodies have a toxic effect on living organisms, causing increased chemical and biological oxygen demand. Some dyes, even in very low concentrations, cause intense colouring. To remove dyes from wastewater, methods such as flotation, oxidation, ozonation, filtration or coagulation with metal compounds are used. Unfortunately, when these methods are used, very large amounts of sludge are produced, which is another problem for the environment. Therefore, one of the methods that can effectively remove dyes from wastewater without creating large amounts of waste is activated carbon adsorption. Adsorption methods in the treatment of wastewater from the dye industry are of particular importance due to their high efficiency, ability to operate over a relatively wide range of concentrations, and availability. The most common adsorbent is activated carbon, which has a high adsorption capacity against many organic compounds. The aim of this study was to determine the effect of filtration rate and type of activated carbon on the removal efficiency of selected cationic (anilan yellow) and anionic (tartrazine) dyes from aqueous solutions.

scholarly journals The influence of ozonation on the activated carbon adsorption of phenol and humic acid

2007 ◽  
Vol 9 (4) ◽  
pp. 107-110 ◽  
Author(s):  
Bożena Seredyńska-Sobecka ◽  
Maria Tomaszewska
Keyword(s):  
Activated Carbon ◽  
Humic Acid ◽  
Oxygen Demand ◽  
Freundlich Isotherm ◽  
Model Solution ◽  
Activated Carbon Adsorption ◽  
Phenol Adsorption ◽  
Isotherm Equation ◽  
Carbon Adsorption

The influence of ozonation on the activated carbon adsorption of phenol and humic acid To study the influence of ozonation on the activated carbon adsorption, a model solution containing approximately 8 mg/dm3 of humic acid and approximately 1 mg/dm3 of phenol has been ozonated, and then adsorption kintetics and adsorption isotherm experiments have been performed. The applied ozone doses ranged from 1 to 3 mg O3/dm3, and a contact time was 1 min. In the adsorption experiments, the commercial activated carbon CWZ-30 (Gryfskand Sp. z o.o., Hajnówka, Poland) has been used. Phenol adsorption under equilibrium conditions was determined by the Freundlich isotherm equation, and the modified Freudlich isotherm equation has been employed for the determination of humic acid equilibrium adsorption. The applied oxidation conditions resulted in color, chemical oxygen demand (COD), total organic carbon (TOC) and UV254 absorbance removal, by 4 - 13%, 3 - 6%, 3 - 7%, respectively. After ozonation, phenol concentration decreased by 6 - 23%. These changes in the model solution did not affect the humic acid adsorption, however, they deteriorated phenol adsorption.

Assessment of Different Binders for Activated Carbon Granulation for the Use in CO2 Adsorption

2021 ◽  
Vol 25 (1) ◽  
pp. 1086-1100
Author(s):  
Pauls Argalis ◽  
Ilze Jerane ◽  
Aivars Zhurinsh ◽  
Kristine Vegere
Keyword(s):  
Activated Carbon ◽  
Polyvinyl Acetate ◽  
Activated Carbons ◽  
Phenol Formaldehyde ◽  
Granular Activated Carbon ◽  
Phenol Formaldehyde Resin ◽  
Waste Materials ◽  
Carbon Adsorbents ◽  
Formaldehyde Resin ◽  
Gas Generator

Abstract An eco-friendly method for the synthesis of granular activated carbon was developed in this study. Two types of activated carbon and three types of activated carbon granules have been obtained using different binders, and their properties have been determined. The approach requires adding other binders and waste materials to improve the granulation of activated carbon. Activated carbon was prepared from birch wood chips. Prepared carbon was granulated with a) gas generator tar, b) phenol-formaldehyde resin, and c) polyvinyl acetate to obtain granular activated carbon. This work aims to study the possibilities of using activated carbon adsorbents for CO2 adsorption. The activated carbon produced was characterized by BET, FTIR, and SEM. The adsorption behavior on CO2 was also studied. Granular activated carbons compression strength was enough to study it in an adsorption bed, and an optimal binder was to be phenol-formaldehyde resin and polyvinyl acetate. The obtained results show that activated carbon granules are suitable for CO2 adsorption and can be used, for example, for the removal of CO2 in the biogas upgrading process. As the sustainability problems are increasing, granules from waste materials could be promising materials for further studies.

Microwave Preparation of Modified Activated Carbons for Phenol Adsorption in Aqueous Solution

2013 ◽  
Vol 726-731 ◽  
pp. 1883-1889
Author(s):  
Brim Stevy Ondon ◽  
Bing Sun ◽  
Zhi Yu Yan ◽  
Xiao Mei Zhu ◽  
Hui Liu
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Activated Carbons ◽  
Microwave Energy ◽  
Adsorptive Capacity ◽  
Obvious Effect ◽  
Phenol Adsorption ◽  
Adsorption Capacities ◽  
Modified Activated Carbons

Microwave energy was used to prepare modified activated carbons (GAC, GAC/MW, GAC/Ni, and GAC/Cu). The modified activated carbons were used for phenol adsorption in aqueous solution. The adsorption conditions were optimized. Adsorption capacities of the different modified activated carbons were evaluated. The effect of microwave pretreatment of activated carbons was investigated. A comparative study on the activated carbons adsorption capacities was also investigated. Under optimal conditions the results showed that there was no obvious effect on activated carbons adsorption when rising temperature and pH during the adsorption process. Stirring has a very high effect on the activated carbons adsorption capacity. The adsorption capacity of the modified activated carbons reaches 95%. MW/GAC, GAC/Ni and GAC/Cu adsorptive capacity was higher compared to the Granulated Activated Carbon (GAC) used as received. GAC treated with microwave energy has highest adsorption capacity. The adsorption capacity of GAC loaded with ion Ni2+ is higher than the activated carbon loaded with Cu2+. The untreated GAC has the lowest adsorption capacity. These results can be explained by the effect of microwave irradiation on GAC.The activated carbon loaded with Ni2+ adsorbs more microwave energy than the GAC loaded with Cu2+.

scholarly journals Nitrate Adsorption by Activated Carbon

2021 ◽  
Vol 23 ◽  
Author(s):  
Adam Rosenblum
Keyword(s):  
Activated Carbon ◽  
Chemical Reactions ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Activated Carbon Adsorption ◽  
Carbon Adsorption ◽  
Food And Beverage ◽  
Nitrate Adsorption ◽  
Odor Removal ◽  
Adsorption Rates

Activated carbon is a type of carbon that is a known catalyst for a variety of chemical reactions. Uses of activated carbon include purifying liquids and gases, food and beverage processing, odor removal, industrial pollution control, and numerous other applications. There are a variety of different activated carbons, with most being derived from coal, peat, and wood. Activated carbon is a catalyst because the small pores of the carbon increase the surface area available for adsorption or chemical reactions. One primary use of activated carbon is how it adsorbs nitrates onto its surface. This paper delves into different adsorption rates of an activated carbon (Filtrasorb 600) that is treated with different chemicals and then subjected to a chemical activation at a constant pressure under different gaseous conditions. Data collected during experiments indicate there are significant interactions between surface functional groups and nitrate.             Keywords: activated carbon, adsorption, nitrates

scholarly journals Low cost activated carbon prepared from Dipterocarpus alatus fruit

2020 ◽  
Vol 3 (SI3) ◽  
pp. first
Author(s):  
Yuvarat Ngernyen ◽  
Werawit Phiewruangnont ◽  
Narathorn Mahantadsanapong ◽  
Chantakorn Patawat ◽  
Ketsara Silakate ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Pore Size ◽  
Surface Area ◽  
Activated Carbons ◽  
Low Cost ◽  
Average Pore Size ◽  
Carbon Adsorbents ◽  
Average Pore ◽  
Maximum Surface ◽  
Dipterocarpus Alatus

Dipterocarpus alatus tree grows prolifically throughout Thailand and can be tapped to yield significant quantities of oil to be used as natural diesel. However, such practices lead to waste dried fruit dropping from the tree. At present, there is no utilization of this dropped fruit, therefore costeffective processes need to be applied to obtain higher value products from this waste. A possible to utilization is the conversion to activated carbon for adsorption applications including the removal of heavy metals, dyes, and other contaminants in water purification and other decontamination process. A major challenge of current commercial activated carbon is the high production cost and recently it has been shown that chemical activators comprise a significant proportion of these costs. This feasibility study investigates the use of Dipterocarpus alatus fruit as raw material to produce low cost activated carbon adsorbents. Activated carbon was prepared from Dipterocarpus alatus fruit: endocarp, mesocarp, and wing by chemical activation with ZnCl2, FeCl3, and KOH. Each part of the fruit was impregnated with 30 wt% activating agent at a ratio of 1:2 for 1 h and then carbonized at 500 oC for a further 1 h. The surface area, pore volume, and average pore size of the resulting carbons were characterized by nitrogen gas adsorption. Activation of mesocarp with ZnCl2, KOH, and FeCl3 gave activated carbons with the surface area of 447, 256, and 199 m2/g, respectively. In the same way, ZnCl2 activation gave a maximum surface area of 312 and 278 m2/g for wing and endocarp, respectively. All of the aforementioned samples have an average pore size of around 2 nm. In contrast, KOH and FeCl3 activation of wing and endocarp produced activated carbon with very low surface area (below 25 m2/g), but with an average pore size of 5- 14 nm. The maximum surface area of activated carbon prepared from Dipterocarpus alatus fruit was higher than some literature examples for activated carbon from other biomass. Consequently, Dipterocarpus alatus fruit demonstrated significant potential as a feedstock for the preparation of low cost activated carbons.

scholarly journals Study of Chromium(VI) Adsorption from Aqueous Solution on to Activated Carbon

2000 ◽  
Vol 18 (2) ◽  
pp. 97-106 ◽  
Author(s):  
Ryszard Dobrowolski ◽  
Elżbieta Stefaniak
Keyword(s):  
Activated Carbon ◽  
Ionic Strength ◽  
Adsorption Capacity ◽  
Activated Carbons ◽  
Principal Mechanism ◽  
Ph Values ◽  
Chromium Vi ◽  
Major Process ◽  
Dilute Aqueous Solutions ◽  
Ppm Level

The adsorption of chromium(VI) from dilute aqueous solutions on to activated carbons at natural pH values was investigated. The activated carbons were modified to obtain materials with a well-defined surface containing inorganic impurities at ppb or ppm level. Measurements of the adsorption kinetics relative to the degree of granulation were undertaken. It was found that the reaction rate of the ions on the surface of the activated carbon rather than diffusion was the major process influencing the equilibrium. Surface reduction of CrVI to CrIII appeared to be the principal mechanism for the adsorption of chromium on the activated carbons studied. It was demonstrated experimentally that the presence of oxidizing agents dramatically changed the adsorption capacity of CrVI on the studied carbons. The influence of the ionic strength (controlled by the addition of NaCl) on the adsorption capacity was also studied. Variable and complex influences of the ionic strength on the adsorption capacity were observed.

scholarly journals Preparation and characterization of flax, hemp and sisal fiber-derived mesoporous activated carbon adsorbents

2017 ◽  
Vol 36 (1-2) ◽  
pp. 441-457 ◽  
Author(s):  
Melike Dizbay-Onat ◽  
Uday K Vaidya ◽  
Jo Anne G Balanay ◽  
Claudiu T Lungu
Keyword(s):  
Fourier Transform ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Physical Adsorption ◽  
Fourier Transform Infrared ◽  
Sisal Fiber ◽  
Carbon Adsorbents ◽  
Chemical Compositions ◽  
Bast Fibers ◽  
Mesoporous Activated Carbon

The first aim of this study was to investigate mesoporous activated carbon adsorbents from sisal, hemp, and flax fibers by cost-effective methods. Fibers were impregnated with low concentration (20 wt.%) phosphoric acid. Carbonization temperatures were defined by thermal analysis. Bast fibers (hemp, flax) decompose at lower temperatures (419.36℃, 434.96℃) than leaf fibers (sisal, 512.92℃). The second aim was to compare bast and leaf fibers-derived activated carbon adsorbents by determining physical adsorption properties, chemical compositions, scanning electron microscope, and Fourier transform infrared spectroscopy. Results showed that natural fibers have good candidates to prepare mesoporous activated carbon adsorbents with high surface area (1186–1359 m2/g), high mesopore percentage (60–72%), and high C content (80–86%). Even though leaf-derived activated carbon developed more mesoporous structure (72%), bast-derived activated carbons provided higher surface areas (Shemp = 1359 m2/g; Sflax = 1257 m2/g) and C content. Fourier transform infrared spectra for bast fibers-derived activated carbon adsorbents were quite similar while leaf fiber-derived activated carbon adsorbent had a different spectrum.

scholarly journals Kinetic studies on the adsorption of phenol from aqueous solution by coffee husk activated carbon

2020 ◽  
Vol 10 (7) ◽  
pp. 676
Author(s):  
Huu Son Ta ◽  
Khu Le Van ◽  
Thu Thuy Luong Thi ◽  
Thanh Hoa Ha
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Kinetic Studies ◽  
Koh Activation ◽  
Phenol Adsorption ◽  
Coffee Husk ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Kinetics Of

The kinetics of phenol adsorption from aqueous solution on activated carbons (ACs) obtained from coffee husk by potassium Hydroxide (KOH) activation at 650 and 750<sup>o</sup>C have been studied in the range of     100-250 mg L<sup>-1</sup> initial phenol concentrations and at the temperatures range of 10 – 40<sup>o</sup>C. Kinetic models for phenol adsorption were evaluated using pseudo-first-order, pseudo-second-order, and Elovich models. The adsorption mechanism was investigated using Reichenberg, Boyd, and Weber and Morris models. The adsorption on coffee husk activated carbon was found to be a fast or speedy process with the adsorption rate, k<sub>2</sub>q<sub>e</sub>, in the range of 0.130 to 0.977 min<sup>-1</sup>. The adsorption process was mainly physical and promoted by chemical sorption and controlled not only by intra-particle diffusion but also by pore diffusion throughout the entire adsorption period.

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