The Effect of Chitosan’s Addition to Resorcinol/Formaldehyde Xerogels on the Characteristics of Resultant Activated Carbon

Hybrid chitosan-resorcinol/formaldehyde xerogels were synthesized, and the effect of including minor quantities of chitosan on the consequent activated carbon was investigated. The resulting activated carbon were characterized by different techniques. Clear changes were found in the structure of activated carbon as a result of including chitosan in the synthesis. The results showed that the disorder ratio of crystal lattice decreased from 0.750 to 0.628 when increasing the concentration of chitosan from 0 to 0.037 wt%. The micropores increased from ~0.3% to ~1.0%, mesopores increased from ~11.2% to ~32.9% and macropores decreased from ~88.4% to ~66.1%. The total pore volume decreased from 1.040 to 0.238 cm3/g and the total pore surface area decreased from 912.3 to 554.4 m2/g. On the other hand, the average pore width decreased from 2.3 to 0.8 nm and the average particle size decreased from 224 to 149 nm. Nano-scale Scanning Electron Microscope (NanoSEM) morphology indicated a critical composition of chitosan (0.022 wt%) that affects the structure and thermal stability of activated carbon produced.

Download Full-text

Preparation of High-Performance Activated Carbon from Coffee Grounds after Extraction of Bio-Oil

Molecules ◽

10.3390/molecules26020257 ◽

2021 ◽

Vol 26 (2) ◽

pp. 257

Author(s):

Jie Ren ◽

Nanwei Chen ◽

Li Wan ◽

Guojian Li ◽

Tao Chen ◽

...

Keyword(s):

Activated Carbon ◽

High Performance ◽

Average Pore Size ◽

Total Pore Volume ◽

Micropore Volume ◽

Bet Surface Area ◽

Average Pore ◽

Activation Temperature ◽

Coffee Grounds ◽

Bio Oil

In this study, a new method for economical utilization of coffee grounds was developed and tested. The resulting materials were characterized by proximate and elemental analyses, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption–desorption at 77 K. The experimental data show bio-oil yields reaching 42.3%. The optimal activated carbon was obtained under vacuum pyrolysis self-activation at an operating temperature of 450 °C, an activation temperature of 600 °C, an activation time of 30 min, and an impregnation ratio with phosphoric acid of 150 wt.%. Under these conditions, the yield of activated carbon reached 27.4% with a BET surface area of 1420 m2·g−1, an average pore size of 2.1 nm, a total pore volume of 0.747 cm3·g−1, and a t-Plot micropore volume of 0.428 cm3·g−1. In addition, the surface of activated carbon looked relatively rough, containing mesopores and micropores with large amounts of corrosion pits.

Download Full-text

Effect of soil textural characteristics on longitudinal dispersion in saturated porous media

Journal of Hydrology and Hydromechanics ◽

10.2478/johh-2021-0004 ◽

2021 ◽

Vol 69 (2) ◽

pp. 161-170

Author(s):

Mojtaba G. Mahmoodlu ◽

Amir Raoof ◽

Martinus Th. van Genuchten

Keyword(s):

Particle Size ◽

Dispersion Coefficient ◽

Average Particle Size ◽

Longitudinal Dispersion ◽

Average Particle ◽

Sand Sample ◽

Average Pore ◽

Advection Dispersion ◽

Strong Positive Relationship

Abstract This study focuses on the effects of soil textural heterogeneity on longitudinal dispersion under saturation conditions. A series of solute transport experiments were carried out using saturated soil columns packed with two filter sands and two mixtures of these sands, having d50 values of 95, 324, 402, and 480 µm, subjected to four different steady flow rates. Values of the dispersion coefficient (D) were estimated from observed in-situ distributions of calcium chlo-ride, injected as a short nonreactive tracer pulse, at four different locations (11, 18, 25, 36 cm). Analyses of the observed distributions in terms of the standard advection-dispersion equation (ADE) showed that D increased nonlinearly with travel distance and higher Peclet numbers+. The dispersion coefficient of sand sample S1 with its largest average particle size (d 50) was more affected by the average pore-water velocity than sample S4 having the smallest d 50. Results revealed that for a constant velocity, D values of sample S1 were much higher than those of sample S4, which had the smallest d 50. A correlation matrix of parameters controlling the dispersion coefficient showed a relatively strong positive relationship between D and the Peclet number. In contrast, almost no correlation was evident between D and porosity as well as grain size. The results obtained with the four sandy matrices were consistent and proved that the dispersion coefficient depends mainly on the particle size.

Download Full-text

Changes in Particle Size Distributions on a Fixed Bed of Granular Activated Carbon

Water Science & Technology ◽

10.2166/wst.1986.0004 ◽

1986 ◽

Vol 18 (1) ◽

pp. 31-42 ◽

Cited By ~ 6

Author(s):

E. A. Shpirt ◽

K. T. Alben

Keyword(s):

New York ◽

Particle Size ◽

Activated Carbon ◽

Average Particle Size ◽

Fixed Bed ◽

Treatment Plant ◽

Granular Activated Carbon ◽

Water Treatment Plant ◽

Average Diameter ◽

Average Particle

The particle size distribution at different bed depths of a fixed bed of granular activated carbon (GAC) has been monitored during 50 weeks of a pilot column run at the Waterford, New York potable water treatment plant. Initial backwashing resulted in significant stratification of GAC in the column: larger particles (average diameter 1.18 mm) settled in the bottom of the column (105 cm), and smaller particles (average diameter 0.97 mm) were concentrated near the top (24 cm), compared to samples of unstratified virgin Calgon F400 (average diameter 1.09 mm). During column loading and initial backwashing, more fines were created than were present in the virgin GAC (average 6.5% of GAC fines in the > 40 mesh fraction, compared to only 0.3% in the > 40 mesh fraction for virgin Calgon F400). After 50 weeks of service there was an overall trend toward a smaller average particle size (0.9 mm) with development of a more regular pattern of bed stratification (1.08 mm at the bottom and 0.75 mm at the top). These changes are attributed to breaking of large particles (12-20 mesh) and creation of intermediate size particles (20-30 and 30-40 mesh).

Download Full-text

Single and competitive adsorption of Cd(II) and Pb(II) from aqueous solution by activated carbon prepared with Salix matsudana Kiodz

Water Science & Technology ◽

10.2166/wst.2016.428 ◽

2016 ◽

Vol 74 (12) ◽

pp. 2751-2761 ◽

Cited By ~ 7

Author(s):

Yan Shu ◽

Kelin Li ◽

Jinfeng Song ◽

Bing Li ◽

Chunfang Tang

Keyword(s):

Activated Carbon ◽

Ph Value ◽

Total Pore Volume ◽

Maximum Adsorption Capacity ◽

Single Element ◽

Acid Activation ◽

Adsorption Model ◽

Adsorption Selectivity ◽

Average Pore ◽

Salix Matsudana

In this study, Salix matsudana activated carbon (SAC) was prepared by phosphoric acid activation, and the adsorption characteristics of Cd(II) and Pb(II) on SAC in single- and double-component solutions were investigated. In both systems, the adsorption capacities of both ions on SAC increased with the increasing initial pH value and temperature in the solutions, and the adsorption equilibrium was approached at 10 min. The adsorption process was spontaneous, endothermic, and depicted well by the pseudo-second-order adsorption model, and the equilibrium adsorption fitted reasonably well with the Langmuir isotherm. The maximum adsorption capacity (Qm) of Cd(II) and Pb(II) was 58.48 and 59.01 mg/g, respectively, in the single-element systems. However, it reduced to 25.32 and 31.09 mg/g, respectively, in the double-element system. The physicochemical property analysis showed that the specific surface area, total pore volume, and average pore diameter of SAC was 435.65 m2/g, 35.68 mL/g, and 3.86 nm, respectively. The SAC contained groups of -OH, C = O, and P = O. Results suggest that SAC had a good performance for the adsorption of Cd(II) and Pb(II) from solution, and the adsorption selectivity sequence was Pb(II) > Cd(II).

Download Full-text

Synthesis and Electrochemical Performance of Polyacrylonitrile Carbon Nanostructure Microspheres for Supercapacitor Application

Journal of Nanomaterials ◽

10.1155/2015/246093 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Mimgjie Ma ◽

Chao Zhang ◽

Guangxu Huang ◽

Baolin Xing ◽

Yuling Duan ◽

...

Keyword(s):

Electron Microscopy ◽

Specific Capacitance ◽

Functional Groups ◽

Photoelectron Spectroscopy ◽

Average Particle Size ◽

Total Pore Volume ◽

Average Particle ◽

Carbon Nanostructure ◽

Activation Temperature ◽

Supercapacitor Application

Polyacrylonitrile (PAN) carbon nanostructure microspheres (CNM) with the average particle size of 200 nm were prepared in the range of 500 to 800°C. The precursors of CNM were obtained through soap-free emulsion polymerization followed by freeze drying, oxidative stabilization, and half-carbonization. KOH was employed as the activation agent of the precursor material, and the ratio between KOH and the precursor was selected as 2 : 1. The element content, pore structure, nitrogen-containing functional groups, and microstructure characterization were characterized via elemental analysis, N2adsorption at low temperature, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and the electrochemical properties were examined as well. The results revealed that the CNM displayed specific surface area as high as 2134 m2/g and the total pore volume could reach 2.01 cm3/g when the activation temperature was 700°C. Furthermore, its specific capacitance in 3 M KOH and 1 M organic electrolyte could reach 311 F/g and 179 F/g, respectively. And, also, abundant functional groups of N-5 and N-6 were rich in the surface of the material, which could cause Faraday reaction and got the increasing specific capacitance via improvement of the wettability of the electrode material.

Download Full-text

Single-Stage Microwave-Assisted Coconut-Shell-Based Activated Carbon for Removal of Dichlorodiphenyltrichloroethane (DDT) from Aqueous Solution: Optimization and Batch Studies

International Journal of Chemical Engineering ◽

10.1155/2021/9331386 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Azrina Aziz ◽

Mohamad Nasran Nasehir Khan ◽

Mohamad Firdaus Mohamad Yusop ◽

Erniza Mohd Johan Jaya ◽

Muhammad Azan Tamar Jaya ◽

...

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Radiation Power ◽

Total Pore Volume ◽

Single Stage ◽

Coconut Shell ◽

Bet Surface Area ◽

Adsorption System ◽

Average Pore ◽

Preparation Conditions

This research aims to optimize preparation conditions of coconut-shell-based activated carbon (CSAC) and to evaluate its adsorption performance in removing POP of dichlorodiphenyltrichloroethane (DDT). The CSAC was prepared by activating the coconut shell via single-stage microwave heating under carbon dioxide, CO2 flow. The total pore volume, BET surface area, and average pore diameter of CSAC were 0.420 cm3/g, 625.61 m2/g, and 4.55 nm, respectively. The surface of CSAC was negatively charged shown by the zeta potential study. Response surface methodology (RSM) revealed that the optimum preparation conditions in preparing CSAC were 502 W and 6 min for radiation power and radiation time, respectively, which corresponded to 84.83% of DDT removal and 37.91% of CSAC’s yield. Adsorption uptakes of DDT were found to increase with an increase in their initial concentration. Isotherm study revealed that DDT-CSAC adsorption system was best described by the Langmuir model with monolayer adsorption capacity, Qm of 14.51 mg/g. The kinetic study confirmed that the pseudo-second-order model fitted well with this adsorption system. In regeneration studies, the adsorption efficiency had slightly dropped from 100% to 83% after 5 cycles. CSAC was found to be economically feasible for commercialization owing to its low production cost and high adsorption capacity.

Download Full-text

Study of activated carbon characteristic from ketaping fruit shell (Terminalia Catappa) as supercapasitors electrode

Journal of Aceh Physics Society ◽

10.24815/jacps.v10i1.17755 ◽

2020 ◽

Vol 10 (1) ◽

pp. 1-6

Author(s):

Rahma Joni ◽

Syukri Syukri ◽

Hermansyah Aziz

Keyword(s):

Activated Carbon ◽

Surface Area ◽

Gas Flow ◽

Total Pore Volume ◽

Amorphous Structure ◽

Koh Activation ◽

Activation Process ◽

Average Pore ◽

Average Pore Radius ◽

Terminalia Catappa

Studi karakteristik karbon aktif dari cangkang buah ketaping (Terminalia Catappa) sebagai elektroda superkapasitor telah diteliti. Karbon aktif dari cangkang buah ketaping (CBK) disiapkan dengan proses karbonisasi pada suhu 400oC dan Proses aktivasi KOH pada suhu 800oC di bawah aliran gas N2. Karbon aktif CBK memiliki kandungan karbon dengan massa atomik sebesar 97,52%. Karbon aktif CBK memiliki struktur amorf dengan dua buah puncak yang lebar pada sudut 2θ yaitu 24,93o dan 42,93o yang bersesuaian dengan bidang (002) dan (100). Karbon aktif CBK yang dihasilkan memiliki pola serapan dengan jenis ikatan OH, C-H, C=O, dan C=C. Adanya ikatan OH dan C=O menunjukkan bahwa arang aktif yang dihasilkan cenderung bersifat lebih polar. Morfologi permukaan karbon aktif CBK menunjukan distribusi ukuran pori yang merata dan luas permukaan yang besar. Luas permukaan spesifik karbon aktif dari CBK adalah 799,892 m2×g-1 dengan volume total pori 0,080 cm3×g-1 dan jari-jari pori rata-rata 1,9072 nm. Kapasitansi spesifik dari karbon aktif dari CBK adalah sebesar 125,446 F×g-1. Studies on the characteristics of activated carbon from ketaping fruit shells (Terminalia Catappa) as supercapacitor electrodes have been studied. Activated carbon from ketaping fruit shells (KFS) prepared by carbonization process at 400oC and the KOH activation process is carried out at 800oC under N2 gas flow. Activated carbon KFS has a carbon content with 97.52% of atomic mass. Activated carbon KFS has an amorphous structure with two wide peaks at an angle of 2θ 24.93ᵒ and 42.93ᵒ corresponding to the plane (002) and (100). Activated carbon KFS produced has an absorption pattern with OH, C-H, C = O, and C = C bond types. The presence of OH and C = O bonds indicates that the activated charcoal produced tends to be more polar. The surface morphology of activated carbon KFS shows an even distribution of pore size and large surface area. The specific surface area of activated carbon KFS is 799.892 m2×g-1 with a total pore volume 0.080 cm3×g-1 and an average pore radius of 1.9072 nm. The specific capacitance value of activated carbon KFS is 125.444 F×g-1.Keywords: Ketaping, Activated Carbon, Supercapacitor, Activator, Capacitance.

Download Full-text

The Production and Characterization of Activated Carbon Electrodes from Pineapple Leaf Fibers for Supercapacitor Application

Journal of Aceh Physics Society ◽

10.24815/jacps.v9i1.14895 ◽

2020 ◽

Vol 9 (1) ◽

pp. 1-8

Author(s):

Agustino Agustino ◽

Rakhmawati Farma ◽

Erman Taer

Keyword(s):

Activated Carbon ◽

Chemical Activation ◽

Total Pore Volume ◽

Amorphous Structure ◽

Physical Activation ◽

Carbon Electrode ◽

Average Pore ◽

Average Pore Radius ◽

Supercapacitor Application

Elektroda karbon aktif berbasis serat daun nanas (SDN) telah berhasil diproduksi dengan proses tiga langkah berikut ini, yaitu: (i) aktivasi kimia, (ii) karbonisasi, dan (iii) aktivasi fisika. Aktivasi kimia dilakukan dengan menggunakan agen pengaktif KOH dengan konsetrasi 0,3 M. Karbonisasi dilakukan dalam lingkungan gas N2 pada temperatur 600oC dan diikuti oleh aktivasi fisika pada temperatur 850oC menggunakan gas CO2 selama 2,5 jam. Luas permukaan spesifik elektroda 512,211 m2×g-1 dengan volume total pori sebesar 0,093 cm3×g–1, dan jari-jari pori rata-rata 1,199 nm. Morfologi permukaan elektroda karbon aktif menunjukkan adanya serat karbon dengan diameter serat dalam kisaran 101 - 185 nm dan memliki kandungan karbon dengan massa atomik sebesar 84,33%. Elektroda karbon aktif memiliki struktur amorf, yang ditunjukkan oleh dua puncak difraksi yang lebar pada sudut hamburan 24,64 dan 43,77o yang bersesuaian dengan bidang (002) dan (100). Kapasitansi spesifik, energi spesifik dan daya spesifik sel superkapasitor yang dihasilkan masing-masing sebesar 110 F×g-1, 15,28 Wh×kg-1 dan 36,69 W×kg-1. Pineapple leaf fiber (PALF) based activated carbon electrode has been successfully produced using three-step process, i.e. (i) chemical activation, (ii) carbonization, and (iii) physical activation. The chemical activation was carried out using KOH activating agent with a concentration of 0.3 M. The carbonization process is conducted out in N2 gas environment at 600oC and followed by physical activation at a temperature of 850oC by using CO2 gas for 2.5 h. The specific surface area of the electrode is 512.211 m2×g-1 with a total pore volume of 0.093 cm3×g-1, and average pore radius of 1.199 nm. The surface morphology of the electrode shown the carbon fibers with diameter in the range of 101 - 185 nm and carbon content with 84.33% of atomic mass. The activated carbon electrode has an amorphous structure, which is shown by two wide diffraction peaks at scattering angles of 24.64 and 43.77o which correspond to the plane (002) and (100), respectively. The specific capacitance, energy and power of the electrode are 110 F×g-1, 15.28 Wh×kg-1 and 36.69 W×kg-1, respectively.Keywords: Serat daun nanas, Kalium hidroksida, Elektroda karbon aktif, Kapasitansi spesifik, Superkapasitor

Download Full-text

Adsorption of phosphorus onto nanoscale zero-valent iron/activated carbon: removal mechanisms, thermodynamics, and interferences

Journal of Water Reuse and Desalination ◽

10.2166/wrd.2022.103 ◽

2022 ◽

Author(s):

Adel Adly ◽

Nagwan G. Mostafa ◽

Abdelsalam Elawwad

Keyword(s):

Activated Carbon ◽

Removal Efficiency ◽

Kinetic Models ◽

Average Particle Size ◽

Zero Valent Iron ◽

Solution Temperature ◽

Average Particle ◽

Phosphorus Adsorption ◽

Removal Mechanisms ◽

Nanoscale Zero Valent Iron

Abstract This study investigated removal mechanisms, thermodynamics, and interferences of phosphorus adsorption onto nanoscale zero-valent iron (nZVI)/activated carbon composite. Activated carbon was successfully used as support for nZVI particles to overcome shortcomings of using nZVI include its tendency to aggregate and separation difficulties. A comprehensive characterization was done for the composite particles, which revealed a high specific surface area of 72.66 m2/g and an average particle size of 37 nm. Several adsorption isotherms and kinetic models have been applied to understand the removal mechanisms. Adsorption isotherm is best fitted by Freundlich and Langmuir models, which indicates that the estimated maximum phosphorus adsorption capacity is 53.76 mg/g at pH 4. Adsorption kinetics showed that the chemisorption process behaved according to a pseudo-second-order model. An adsorption mechanism study conducted using the intra-particle diffusion and Boyd kinetic models indicated that the adsorption rate is limited by surface diffusion. A thermodynamic study showed that phosphorus removal efficiency increased as the solution temperature increased from 15 to 37 °C. Finally, the results of an interference study showed that the presence of Ni2+, Cu2+, Ca2+, Na+ cations, nitrate ions (), and sodium acetate improves removal efficiency, while the presence of sulfate ions () and urea reduces removal efficiency.

Download Full-text

Preparation of Activated Carbon from Blue Coke Powder and its Adsorption Properties of Cr(VI)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.156-157.1347 ◽

2010 ◽

Vol 156-157 ◽

pp. 1347-1351 ◽

Cited By ~ 1

Author(s):

Yu Hong Tian ◽

Xin Zhe Lan ◽

Lin Bo Li ◽

Xiang Yang Chen ◽

Tang Hua Hu

Keyword(s):

Activated Carbon ◽

Average Pore Size ◽

Total Pore Volume ◽

Adsorption Properties ◽

Physical Activation ◽

Order Kinetic ◽

Average Pore ◽

Endothermic Process ◽

Powder Activated Carbon ◽

Coke Powder

Activated carbon was prepared from blue coke powder by physical activation. The results show that the specific surface area (BET) is 697.05m2/g, the total pore volume is 0.4569cm3/g and the average pore size is 2.6221nm. The adsorption properties of Cr( ) onto blue coke powder activated carbon are discussed from the kinetics and thermodynamics viewpoints. The pseudo-second-order kinetic model shows the best correlation with experimental data. Langmuir and Freundlich models are used to fit the equilibrium, and it is indicated that Freundlich best fits these data. The adsorption of Cr( ) onto blue coke powder activated carbon is found to be an endothermic process in nature.

Download Full-text