Adsorption characteristics of Bisphenol-A on tailored activated carbon in aqueous solutions

The adsorption behavior of pharmaceuticals and personal care product, Bisphenol-A (BPA), according to four coal-based and four wood-based granular activated carbons modified using outgassing treatment, acidic treatment or alkaline treatment was studied. The adsorption isotherm results indicated that carbon surface acidity played a very important role in the adsorption of BPA. It was found that increasing surface acidity would increase the hydrogen bonding effects and increase adsorption of BPA on activated carbon. The acidic modified sample (F600-A and OLC-A) represented the best adsorption capacity, and the equilibrium adsorption amounts reached 346.42 and 338.55 mg/g, respectively. Further, effects of surface charge and surface basicity were examined. It was found that the adsorbed amount of BPA decreased with the increase of surface charge. Finally, there appeared to be a significant oligomerization phenomenon with BPA molecules onto the surface of activated carbon. OLC and OLC-OG, which have higher micropore percentages, are very effective in hampering the oligomerization of BPA under oxic conditions.

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Effect of Polyphosphate on Removal of Endocrine-Disrupting Chemicals of Nonylphenol and Bisphenol-A by Activated Carbons

Water Quality Research Journal ◽

10.2166/wqrj.2005.052 ◽

2005 ◽

Vol 40 (4) ◽

pp. 484-490 ◽

Cited By ~ 5

Author(s):

Keun J. Choi ◽

Sang G. Kim ◽

Chang W. Kim ◽

Seung H. Kim

Keyword(s):

Activated Carbon ◽

Bisphenol A ◽

Surface Charge ◽

Activated Carbons ◽

Endocrine Disrupting Chemicals ◽

Dipole Interaction ◽

High Affinity ◽

Calcium Polyphosphate ◽

Endocrine Disrupting ◽

Positively Charged

Abstract This study examined the effect of polyphosphate on removal of endocrine-disrupting chemicals (EDCs) such as nonylphenol and bisphenol-A by activated carbons. It was found that polyphosphate aided in the removal of nonylphenol and bisphenol- A. Polyphosphate reacted with nonylphenol, likely through dipole-dipole interaction, which then improved the nonylphenol removal. Calcium interfered with this reaction by causing competition. It was found that polyphosphate could accumulate on carbon while treating a river. The accumulated polyphosphate then aided nonylphenol removal. The extent of accumulation was dependent on the type of carbon. The accumulation occurred more extensively with the wood-based used carbon than with the coal-based used carbon due to the surface charge of the carbon. The negatively charged wood-based carbon attracted the positively charged calcium-polyphosphate complex more strongly than the uncharged coal-based carbon. The polyphosphate-coated activated carbon was also effective in nonylphenol removal. The effect was different depending on the type of carbon. Polyphosphate readily attached onto the wood-based carbon due to its high affinity for polyphosphate. The attached polyphosphate then improved the nonylphenol removal. However, the coating failed to attach polyphosphate onto the coal-based carbon. The nonylphenol removal performance of the coal-based carbon remained unchanged after the polyphosphate coating.

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The interaction of metallic ions onto activated carbon surface using computational chemistry software

Adsorption Science & Technology ◽

10.1177/0263617420919234 ◽

2020 ◽

Vol 38 (5-6) ◽

pp. 191-204

Author(s):

AL Paredes-Doig ◽

A Pinedo-Flores ◽

J Aylas-Orejón ◽

D Obregón-Valencia ◽

MR Sun Kou

Keyword(s):

Activated Carbon ◽

Metal Ions ◽

Electron Density ◽

Activated Carbons ◽

Surface Acidity ◽

Chemical Activation ◽

Carbon Surface ◽

Maximum Adsorption Capacity ◽

Metallic Ions ◽

Oxidized Activated Carbon

Activated carbon was prepared from the seeds of aguaje palm ( Mauritia flexuosa L.f.) by a chemical activation with phosphoric acid. This activated carbon was used for adsorbing metal ions: Pb(II), Cd(II), and Cr(III). To understand the mechanism of adsorption of these heavy metals (Cr, Cd, and Pb), the activated carbon surface was oxidized with nitric acid (1 M) increasing the oxygenated surface groups showing an increasing in their adsorption capacities of these metals. The oxidized activated carbon slightly increased the maximum adsorption capacity to 5–7%. The order of adsorption for unoxidized and oxidized activated carbons was Pb> Cd> Cr. This experimental information was corroborated by molecular modeling program Hyperchem 8 based adsorption mainly on two factors: the electron density and orbitals—highest occupied molecular orbital and lowest unoccupied molecular orbital.Activated carbons were characterized by adsorption/desorption of N2, obtaining an increase of microporous surface area for oxidized activated carbon. An increase of surface acidity and a reduction of isoelectric points were observed in oxidized activated carbon. According to these results, the adsorption of metal ions is favored in contact with an oxidized activated carbon, which has more amount of phenolic and carboxylic functional groups. Similarly, decreasing the isoelectric point indicates that the surface has a higher negative charge. The surface information was corroborated by Hyperchem, which indicates that the surface of the oxidized activated carbon has a higher electron density, indicating a larger amount of electrons on its surface, which means the surface of oxidized activated carbon charges negatively and thereby attracts metal ions.

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Modification of the surface chemistry of activated carbon and its influence on methylene blue adsorption

Jurnal Teknik Kimia Indonesia ◽

10.5614/jtki.2006.5.1.6 ◽

2018 ◽

Vol 5 (1) ◽

pp. 374

Author(s):

David Wibowo ◽

Lanny Setyadhi ◽

Suryadi Ismadji

Keyword(s):

Methylene Blue ◽

Activated Carbon ◽

Surface Chemistry ◽

Activated Carbons ◽

Surface Acidity ◽

Carbon Surface ◽

Point Of Zero Charge ◽

Titration Method ◽

Zero Charge ◽

Boehm Titration

The adsorption behavior of activated carbons is determined not only by their porous structures but also by the chemical nature of its surface. The surface chemistry of activated carbons can be selectively modified in order to improve their adsorption capacity. In this study, a NORIT granular activated carbon was treated by oxidant (HNO3) and non-oxidant acid (HCI) at different concentrations and temperatures. The surface chemistries of the materials were characterized by Boehm titration method and by the determination of the point of zero charge (pHPZC).The adsorption properties of the selected samples were studied by adsorption of methylene blue, which is one of the important dyes and found in many textile effluents. In addition, the pore structures of the modified carbons were also studied by argon adsorption at 87.29 K. As results, it was observed that both HN03 and HCI treatments could increase the surface acidity of activated carbons. Activated carbons modified by HCI gave the best performance on the adsorption of methylene blue.Keywords: Activated Carbon, Surface Chemistry, Chemical Treatment, Boehm Titration Method, Adsorption AbstrakKemampuan adsorpsi karbon akti.ftidak hanya ditentukan oleh struktur pori tetapijuga dipengaruhi oleh sifat kimia dari permukaannya. Sifat kimia permukaan karbon aktif dapat secara selektif dimodifikasi dengan tujuan untuk lebih meningkatkan kapasitas adsorpsinya. Pada penelitian ini, karbon aktif NORIT granular ditreatment dengan menggunakan asam oksidator (HNO) dan non-oksidator (HCI) pada berbagai konsentrasi dan suhu. Sifat kimia permukaan karbon aktif dikarakterisasi dengan menggunakan metode titrasi Boehm serta dengan penentuan point of zero charge (pHPZC). Kemampuan adsorpsinya diuji dengan mengadsorp larutan methylene blue, dimana methylene blue merupakan salah satu komponen dalam limbah tekstil. Sedangkan struktur pori karbon aktif dianalisa dengan adsorpsi Ar pada suhu 87,29 K. Penelitian ini menunjukkan bahwa baik treatment dengan HNO3 maupun HCI dapat mengakibatkan terjadinya peningkatan sifat asam pada permukaan karbon aktif. Karbon aktif yang diberi perlalatan dengan HCI memberikan kemampuan adsorpsi yang paling baik dalam adsorpsi larutan methylen biru.Kata Kunci: Karbon Aktif, Sifat Kimia Permukaan, Perlakuan dengan Larutan Kimia, Metode Titrasi Boehm, Adsorpsi

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The influence of active carbon contaminants on the ozonation mechanism interpretation

Scientific Reports ◽

10.1038/s41598-021-89510-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lilla Fijołek ◽

Joanna Świetlik ◽

Marcin Frankowski

Keyword(s):

Activated Carbon ◽

Active Carbon ◽

Alkali Metals ◽

Activated Carbons ◽

Carbon Surface ◽

Bulk Solution ◽

Ozone Decomposition ◽

Reaction Products ◽

Treatment Technology ◽

Carbon Impurities

AbstractIn water treatment technology, activated carbons are used primarily as sorbents to remove organic impurities, mainly natural organic matter, but also as catalysts in the ozonation process. Commercially available activated carbons are usually contaminated with mineral substances, classified into two main groups: alkali metals (Ca, Na, K, Li, Mg) and multivalent metals (Al, Fe, Ti, Si). The presence of impurities on the carbon surface significantly affects the pHpzc values determined for raw and ozonated carbon as well as their acidity and alkalinity. The scale of the observed changes strongly depends on the pH of the ozonated system, which is related to the diffusion of impurities from the carbon to the solution. In an acidic environment (pH 2.5 in this work), the ozone molecule is relatively stable, yet active carbon causes its decomposition. This is the first report that indirectly indicates that contaminants on the surface of activated carbon (multivalent elements) contribute to the breakdown of ozone towards radicals, while the process of ozone decomposition by purified carbons does not follow the radical path in bulk solution. Carbon impurities also change the distribution of the reaction products formed by organic pollutants ozonation, which additionally confirms the radical process. The study showed that the use of unpurified activated carbon in the ozonation of succinic acid (SA) leads to the formation of a relatively large amount of oxalic acid (OA), which is a product of radical SA degradation. On the other hand, in solutions with purified carbon, the amount of OA generated is negligible.

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Attachment and Growth of Biomass on Surface-Modified Activated Carbon Fibers

Water Science & Technology ◽

10.2166/wst.1992.0447 ◽

1992 ◽

Vol 26 (3-4) ◽

pp. 665-671 ◽

Cited By ~ 2

Author(s):

K. Kutics ◽

M. Suzuki

Keyword(s):

Activated Carbon ◽

Activated Carbons ◽

Surface Acidity ◽

Calculated Data ◽

Bacterial Biomass ◽

Activated Carbon Fiber ◽

Continuous Stirred Tank Reactor ◽

Modified Activated Carbon ◽

Start Up ◽

Surface Modified

Activated carbon fiber (ACF) was used as a model of commercial activated carbons to examine the effect of surface chemistry on the attachment behavior of bacterial biomass. Surface acidity was found to enhance the biomass-ACF interaction. When ACFs were applied as biomass support media in a continuous stirred tank reactor, surface acidity of the carbon resulted in faster biomass growth in the start-up phase. The start-up phase was simulated by a simple biomass attachment kinetics model. Experimental and calculated data show a reasonable agreement, with the exception of the hydrogenated specimen, which was interpreted by assuming that the hydrogen-reduced surface is highly reactive and then may undergo oxidation in the initial phase of operation so that the adsorption characteristics are altered.

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Quinone/hydroquinone redox couple as a source of enormous capacitance of activated carbon electrodes

MRS Proceedings ◽

10.1557/opl.2013.268 ◽

2013 ◽

Vol 1505 ◽

Cited By ~ 2

Author(s):

Krzysztof Fic ◽

Mikolaj Meller ◽

Grzegorz Lota ◽

Elzbieta Frackowiak

Keyword(s):

Activated Carbon ◽

Redox Reactions ◽

Electrode Materials ◽

Activated Carbons ◽

Hydroxyl Group ◽

Carbon Surface ◽

Carbon Electrodes ◽

Main Subject ◽

Solution Ph ◽

Reversible Redox

ABSTRACTThe main subject of this paper is to examine and to evaluate the capacitive behaviour of activated carbon electrodes electrochemically decorated by quinone-type functional groups. For this purpose, different electrolytes, i.e. hydroquinone, catechol and resorcinol at the concentration of 0.38 mol L-1, dissolved in 1 mol L-1 H2SO4, 1 mol L-1 Li2SO4 and 6 mol L-1 KOH were used. These electrolytes could generate electroactive groups (able to undergo reversible redox reactions) on the surface of electrode material. Apart from typical adsorption of the mentioned dihydroxybenzenes, so called grafting could occur and might cause generation of quinone|hydroquinone functionals on carbon surface. As an effect of functional reversible redox reaction, additional capacitance value, called pseudocapacitance, could be achieved. Hence, besides typical charge originating from charging/discharging of the electrical double layer on the electrode/electrolyte interface, additional capacitance comes also from faradaic reactions. Activated carbons are the most promising electrode materials for this purpose; apart from great physicochemical properties, they are characterized by well-developed specific surface area over 2000 m2 g-1 which results in high capacitance values.In the manuscript the influence of the hydroxyl group location as well as electrolyte solution pH on the electrochemical performance of the electrode is discussed.

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Coal-Based Activated Carbons for the Removal of Sulphur Dioxide via Adsorption

Adsorption Science & Technology ◽

10.1177/026361749701501006 ◽

1997 ◽

Vol 15 (10) ◽

pp. 803-814 ◽

Cited By ~ 4

Author(s):

A.M. Youssef ◽

M.R. Mostafa ◽

E.M. Dorgham

Keyword(s):

Activated Carbon ◽

Low Temperature ◽

Zinc Chloride ◽

Sulphur Dioxide ◽

Activated Carbons ◽

Textural Properties ◽

Nitrogen Adsorption ◽

Carbon Surface ◽

Steam Activation ◽

Pore Widening

Zinc chloride-activated carbons and steam-activated carbons were prepared from Maghara coal. The textural properties were determined from low-temperature nitrogen adsorption. Zinc chloride activation is usually associated with the creation of new micropores while steam activation involves pore widening particularly when the percentage burn-off is high. The adsorption of SO2 on steam-activated carbon is high compared with ZnCl2-activated carbons. Steam activation develops surface basic groups which provide chemisorption sites for SO2. The adsorption of SO2 is enhanced in the presence of O2 and water vapour and involves the formation of sulphuric acid in this case. Sulphur dioxide adsorption is related to the chemistry of the carbon surface rather than to the extent of the surface area of the activated carbon.

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SURFACE MODIFICATIONS OF ACTIVATED CARBON AND ITS IMPACT ON APPLICATION

Surface Review and Letters ◽

10.1142/s0218625x1830006x ◽

2019 ◽

Vol 26 (01) ◽

pp. 1830006 ◽

Cited By ~ 2

Author(s):

MATHEUS PEGO ◽

JANAÍNA CARVALHO ◽

DAVID GUEDES

Keyword(s):

Surface Modification ◽

Activated Carbon ◽

Surface Chemistry ◽

Surface Structure ◽

Adsorption Capacity ◽

Activated Carbons ◽

Surface Modifications ◽

Hazardous Substances ◽

Carbon Surface ◽

Corona Treatment

The main and new surface modification methods of activated carbon (AC) and their influence on application (adsorption capacity) were reviewed. Adsorption capacity is an important issue, contributing to hazardous substances environment management. According to literature, it is true that surface chemistry strongly affects adsorption capacity. Surface chemistry can be modified by several methods that lead to different activated carbon properties. Furthermore, adsorbate properties, and their relationships with surface structure, can impact adsorption properties. Surface modifications can be conducted by adding some atoms to the surface structure, making the surface more acidic or basic. Introduction of oxygen and ammonia atoms (chemical modification) are the main processes to make the surface more acidic and basic, respectively, although may bring chemical wastes to environment. Surface modification is done by chemical and physical modifications that lead activated carbons to present different properties. The main and new methods of chemical and physical modifications are compared and presented in this paper. Some new physical methods, like corona treatment, plasma discharge and microwave radiation, can be applied to cause surface modifications. Corona treatment can be a practical and new way to cause surface modification on an activated carbon surface.

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Removal of Ammonia from Aqueous Solution Using Activated Carbons

Adsorption Science & Technology ◽

10.1177/026361749601300102 ◽

1996 ◽

Vol 13 (1) ◽

pp. 7-13 ◽

Cited By ~ 5

Author(s):

Th. El-Nabarawy ◽

G.A. Fagal ◽

L. B. Khalil

Keyword(s):

Activated Carbons ◽

Surface Acidity ◽

Surface Oxidation ◽

Ammonia Removal ◽

Carbon Surface ◽

Ammonia Adsorption ◽

Surface Areas ◽

Adsorption Of Nitrogen ◽

Oxygen Groups ◽

Modified Activated Carbons

The surface areas of non-activated, activated and modified activated carbons were determined from the adsorption of nitrogen at −196°C and of carbon dioxide at 25°C. The base neutralization capacities were determined from the adsorption of NaOH, Na2CO3, NaHCO3 and NH4OH. The amount of oxygen combined to the carbon surface was estimated by measuring the pressure of CO and CO2 obtained on outgassing the carbon sample in the temperature range 300–1000°C. The surface area of activated carbon is not a determining factor in its ammonia adsorption. The surface acidity of the active carbon is a good measure of its capacity for ammonia removal. Ammonia adsorption increases appreciably upon surface oxidation of carbons with oxidizing gases and solutions. The acidic groups on the surface of carbons differ in their strength. Only a fraction of the surface covered by the carbon–oxygen groups is responsible for the capacity of the carbon towards ammonia. Most of the adsorbed ammonia is recovered upon treatment with dilute hydrochloric acid leaving the surface free for successive ammonia adsorption cycles.

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