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

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.

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.

Influence of activated carbon surface acidity on adsorption of heavy metal ions and aromatics from aqueous solution

2007 ◽  
Vol 253 (20) ◽  
pp. 8554-8559 ◽  
Author(s):  
Sanae Sato ◽  
Kazuya Yoshihara ◽  
Koji Moriyama ◽  
Motoi Machida ◽  
Hideki Tatsumoto
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Activated Carbon ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Surface Acidity ◽  
Carbon Surface

scholarly journals Activated Carbon from Corncobs Doped with RuO2 as Biobased Electrode Material

2021 ◽  
Vol 2 (3) ◽  
pp. 324-343
Author(s):  
Viola Hoffmann ◽  
Catalina Rodriguez Correa ◽  
Saskia Sachs ◽  
Andrea del Pilar Sandoval-Rojas ◽  
Mo Qiao ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Electrochemical Properties ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Xrd Analysis ◽  
High Specific Surface Area ◽  
Carbon Surface ◽  
Physico Chemical ◽  
Electrochemical Double Layer Capacitors ◽  
Electrochemical Double Layer

Bio-based activated carbons with very high specific surface area of >3.000 m² g−1 (based on CO2 adsorption isotherms) and a high proportion of micropores (87% of total SSA) are produced by corncobs via pyrolysis and chemical activation with KOH. The activated carbon is further doped with different proportions of the highly pseudocapacitive transition metal oxide RuO2 to obtain enhanced electrochemical properties and tune the materials for the application in electrochemical double-layer capacitors (EDLC) (supercapacitors). The activated carbon and composites are extensively studied regarding their physico-chemical and electrochemical properties. The results show that the composite containing 40 wt.% RuO2 has an electric conductivity of 408 S m−1 and a specific capacitance of 360 Fg−1. SEM-EDX, XPS, and XRD analysis confirm the homogenous distribution of partly crystalline RuO2 particles on the carbon surface, which leads to a biobased composite material with enhanced electrochemical properties.

scholarly journals Potential Use of Waste Activated Sludge Hydrothermally Treated as a Renewable Fuel or Activated Carbon Precursor

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3534
Author(s):  
J. A. Villamil ◽  
E. Diaz ◽  
M. A. de la Rubia ◽  
A. F. Mohedano
Keyword(s):  
Activated Carbon ◽  
Activated Sludge ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Hydrothermal Carbonization ◽  
Effect Of Temperature ◽  
Waste Activated Sludge ◽  
Maximum Adsorption Capacity ◽  
Porous Network ◽  
Good Potential

In this work, dewatered waste activated sludge (DWAS) was subjected to hydrothermal carbonization to obtain hydrochars that can be used as renewable solid fuels or activated carbon precursors. A central composite rotatable design was used to analyze the effect of temperature (140–220 °C) and reaction time (0.5–4 h) on the physicochemical properties of the products. The hydrochars exhibited increased heating values (up to 22.3 MJ/kg) and their air-activation provided carbons with a low BET area (100 m2/g). By contrast, chemical activation with K2CO3, KOH, FeCl3 and ZnCl2 gave carbons with a well-developed porous network (BET areas of 410–1030 m2/g) and substantial contents in mesopores (0.079–0.271 cm3/g) and micropores (0.136–0.398 cm3/g). The chemically activated carbons had a fairly good potential to adsorb emerging pollutants such as sulfamethoxazole, antipyrine and desipramine from the liquid phase. This was especially the case with KOH-activated hydrochars, which exhibited a maximum adsorption capacity of 412, 198 and 146 mg/g, respectively, for the previous pollutants.

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

2016 ◽  
Vol 74 (7) ◽  
pp. 1744-1751 ◽  
Author(s):  
Liang Yan ◽  
Di Lv ◽  
Xinwen Huang ◽  
Huixiang Shi ◽  
Geshan Zhang
Keyword(s):  
Hydrogen Bonding ◽  
Activated Carbon ◽  
Bisphenol A ◽  
Surface Charge ◽  
Activated Carbons ◽  
Surface Acidity ◽  
Alkaline Treatment ◽  
Carbon Surface ◽  
Personal Care Product ◽  
Surface Basicity

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.

scholarly journals Removal of Heavy Metal Ions from One- and Two-Component Solutions via Adsorption on N-Doped Activated Carbon

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7045
Author(s):  
Justyna Kazmierczak-Razna ◽  
Anetta Zioła-Frankowska ◽  
Piotr Nowicki ◽  
Marcin Frankowski ◽  
Robert Wolski ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Activated Carbon ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Heavy Metal Ions ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Phase Contact ◽  
Phase Contact Time

This paper deals with the adsorption of heavy metal ions (Cu2+ and Zn2+) on the carbonaceous materials obtained by chemical activation and ammoxidation of Polish brown coal. The effects of phase contact time, initial metal ion concentration, solution pH, and temperature, as well as the presence of competitive ions in solution, on the adsorption capacity of activated carbons were examined. It has been shown that the sample modified by introduction of nitrogen functional groups into carbon structure exhibits a greater ability to uptake heavy metals than unmodified activated carbon. It has also been found that the adsorption capacity increases with the increasing initial concentration of the solution and the phase contact time. The maximum adsorption was found at pH = 8.0 for Cu(II) and pH = 6.0 for Zn(II). For all samples, better fit to the experimental data was obtained with a Langmuir isotherm than a Freundlich one. A better fit of the kinetic data was achieved using the pseudo-second order model.

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

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

scholarly journals ADSORPTION OF METHYLENE BLUE ONTO ACTIVATED CARBON DEVELOPED FROM BAOBAB FRUIT SHELL BY CHEMICAL ACTIVATION: KINETIC EQUILIBRIUM STUDIES

2021 ◽  
Vol 22 (2) ◽  
pp. 31-49
Author(s):  
Radhia Nedjai ◽  
Ma’an Fahmi Rashid Alkhatib ◽  
Md Zahangir Alam ◽  
Nassereldeen Ahmed Kabbashi
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Material Surface ◽  
Maximum Adsorption Capacity ◽  
Koh Activation ◽  
Activation Process ◽  
Scanning Electron Micrographs ◽  
Freundlich Model

This article provides results of the usability of baobab fruit shell to produce activated carbons by chemical activation using ZnCl2, H3PO4, and KOH. This study indicated that activated carbon produced from baobab fruit shell fruit can be used as a promising adsorbent for the removal of methylene blue from aqueous solutions. Significant changes on the material surface following the activation process were observed through SEM and FTIR analyses. Scanning electron micrographs of BFS-ACs showed that porous structures were formed during activation, while the FTIR results indicated that the carbons have abundant functional groups on the surface. KOH activation led an activated carbon with a high methylene blue adsorption of 95.54% and maximum adsorption capacity of 113.63 mg/g, which is directly related to the specific surface area of activated carbons. The adsorption isotherm data were fitted to Langmuir and Freundlich adsorption models. The Langmuir isotherm model showed better fit to the equilibrium data than the Freundlich model. The adsorption process was well described by the pseudo-second-order kinetics. The BFS-ACs is an effective and low-cost adsorbent for the removal of MB from an aqueous solution. ABSTRAK: Kajian ini memberi input tentang kebolehgunaan kulit buah baobab bagi menghasilkan karbon teraktifan melalui aktiviti kimia menggunakan ZnCl2, H3PO4, dan KOH. Karbon aktif daripada kulit buah Baobab ini berpotensi sebagai penyerap bagi menyingkir larutan akueus metilin biru. Perubahan ketara pada permukaan bahan diikuti dengan proses pengaktifan dipantau melalui analisis SEM dan FTIR. Imbasan elektron mikrograf BFS-AC menunjukkan struktur porus terhasil semasa proses pengaktifan. Sementara dapatan FTIR menunjukkan karbon mempunyai banyak kumpulan berfungsi pada permukaan. Pengaktifan KOH menghasilkan karbon aktif menggunakan larutan biru metilin yang tinggi sebanyak 95.54% dan kapasiti maksimum penyerapan 113.63 mg/g, iaitu berkadar langsung dengan tumpuan kawasan permukaan karbon aktif berkaitan. Data isoterma penyerapan dibina pada model penyerapan Langmuir dan Freundlich. Model isoterma Langmuir lebih padan pada data keseimbangan berbanding model Freundlich. Proses penyerapan menunjukkan lebih kinetik order-kedua-pseudo. BFS-AC sangat efektif dan penyerap murah bagi membuang MB daripada larutan akues.

Activated carbon from molasses efficiency for Cr(VI), Pb(II) and Cu(II) adsorption: A mechanistic study

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Activated Carbon ◽  
Phosphoric Acid ◽  
Sugar Industry ◽  
Chemical Activation ◽  
High Surface ◽  
High Surface Area ◽  
Mechanistic Study ◽  
Acid Mixture ◽  
Maximum Adsorption Capacity ◽  
Good Potential

Activated carbon was prepared from molasses, which are natural precursors of vegetable origin resulting from the sugar industry. A simple elaboration process, based on chemical activation with phosphoric acid, was proposed. The final product, prepared by activation of molasses/phosphoric acid mixture in air at 500°C, presented high surface area (more than 1400 m2/g) and important maximum adsorption capacity for methylene blue (625 mg/g) and iodine (1660 mg/g). The activated carbon (MP2(500)) showed a good potential for the adsorption of Cr(VI), Cu(II) and Pb(II) from aqueous solutions. The affinity for the three ions was observed in the following order Cu2+ Cr6+ Pb2+. The process is governed by monolayer adsorption following the Langmuir model, with a correlation coefficient close to unity.

scholarly journals The influence of active carbon contaminants on the ozonation mechanism interpretation

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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