scholarly journals Activated carbons from coffee husk: Preparation, characterization, and reactive red 195 adsorption

2020 ◽  
pp. 174751982097046
Author(s):  
Thu Thuy Luong Thi ◽  
Huu Son Ta ◽  
Khu Le Van

Activated carbons are prepared from coffee husks by chemical activation with ZnCl2 and are characterized by employing Brunauer, Emmett and Teller, scanning electron microscopy, Fourier-transform infrared spectroscopy, and Boehm titrations. The effects of ZnCl2/coffee husks, activation temperature, and activation time are studied, and the results show that the sample ACZ3-600-2 has a high surface area of 1383 m2 g−1, a high pore volume of 1.6482 cm3 g−1, and numerous surface functional groups. The adsorption of reactive red 195 onto the prepared coffee husk activated carbon can be well-described by the pseudo-second-order kinetic model and is found to be controlled by film diffusion followed by intra-particle diffusion. The adsorption isotherm data obtained at 10–40 °C are analyzed and found to follow the Sips model at lower temperatures (10 and 20 °C) and the Redlich–Peterson model at higher temperatures (30 and 40 °C). The obtained thermodynamic parameters (Δ G° < 0, Δ H° = 33.487 kJ mol−1, and Δ S° = 202.30 J K−1 mol−1) suggest that the adsorption of reactive red 195 onto the prepared activated carbon is spontaneous, endothermic, and demonstrates an increasing of randomness at the adsorbate–adsorbent interface. The investigated results show that coffee husk activated carbon is an efficient adsorbent for the removal of reactive red 195 from aqueous solutions.

2017 ◽  
Vol 75 (9) ◽  
pp. 2047-2055 ◽  
Author(s):  
Thuan Van Tran ◽  
Quynh Thi Phuong Bui ◽  
Trinh Duy Nguyen ◽  
Van Thi Thanh Ho ◽  
Long Giang Bach

The present study focused on the application of response surface methodology to optimize the fabrication of activated carbon (AC) from sugarcane bagasse for adsorption of Cu2+ ion. The AC was synthesized via chemical activation with ZnCl2 as the activating agent. The central composite design based experiments were performed to assess the individual and interactive effect of influential parameters, including activation temperature, ZnCl2 impregnation ratio and activation time on the AC yield and removal of Cu2+ ion from the aqueous environment. The statistically significant, well-fitting quadratic regression models were successfully developed as confirmed by high F- and low P-values (&lt;0.0001), high correlation coefficients and lack-of-fit tests. Accordingly, the optimum AC yield and removal efficiency of Cu2+ were predicted, respectively, as 48.8% and 92.7% which were approximate to the actual values. By applying the predicted optimal parameters, the AC shows a surprisingly high surface area of around 1,500 m2/g accompanied by large pore volume and narrow micropore size at low fabrication temperature.


2020 ◽  
Vol 11 (3) ◽  
pp. 10265-10277

Activated carbons derived from rice husk pyrolysis (biochar) were prepared by chemical activation at different biochar/K2CO3 proportions in order to assess its capacity as adsorbent. The activated material was characterized by X-ray diffraction (DRX), Raman spectroscopy, scanning electron microscopy (SEM), the Brunauer, Emmet, and Teller (BET) method. The Barret, Joyner, and Halenda (BJH) method and functional density theory (DFT), presenting interesting texture properties, such as high surface area (BET 1850 m2 g-1) and microporosity, which allow its use as a sorbent phase in solid-phase extraction (SPE) of the main constituents of the aqueous pyrolysis phase. It was demonstrated that the activated carbon (RH-AC) adsorbs different compounds present in from rice husk pyrolysis wastewater through quantitative analysis by high-performance liquid chromatography with a diode-array detector (HPLC-DAD), presenting good linearity (R2 > 0.996) at 280 nm.


2014 ◽  
Vol 1644 ◽  
Author(s):  
Paul R. Armstrong ◽  
Zachary J. Morchesky ◽  
Dustin T. Hess ◽  
Kofi W. Adu ◽  
David. K. Essumang ◽  
...  

ABSTRACTWe present preliminary results on a processing protocol by chemical activation that transforms organic waste product such as coconut husk into high surface area activated carbon. Dried raw materials of the coconut husk were carbonized anaerobically into char. The char was impregnated with KOH of different ratios and were activated at 800°C and 900°C. The transmission electron microscope was used to acquire structural and morphological information of the activated carbon, and the surface area and porosity analysis were performed using Micromeritics ASAP 2020 analyzer. The activated carbons show both micropores and mesopores with specific surface area as high as 2900m2/g.


Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4658 ◽  
Author(s):  
Katarzyna Januszewicz ◽  
Anita Cymann-Sachajdak ◽  
Paweł Kazimierski ◽  
Marek Klein ◽  
Justyna Łuczak ◽  
...  

In this work, we present the preparation and characterization of biomass-derived activated carbon (AC) in view of its application as electrode material for electrochemical capacitors. Porous carbons are prepared by pyrolysis of chestnut seeds and subsequent activation of the obtained biochar. We investigate here two activation methods, namely, physical by CO2 and chemical using KOH. Morphology, structure and specific surface area (SSA) of synthesized activated carbons are investigated by Brunauer-Emmett-Teller (BET) technique and scanning electron microscopy (SEM). Electrochemical studies show a clear dependence between the activation method (influencing porosity and SSA of AC) and electric capacitance values as well as rate capability of investigated electrodes. It is shown that well-developed porosity and high surface area, achieved by the chemical activation process, result in outstanding electrochemical performance of the chestnut-derived porous carbons.


2019 ◽  
Vol 8 (3) ◽  
pp. 168-178 ◽  
Author(s):  
Mohammed Kachabi ◽  
Imane El Mrabet ◽  
Zineb Benchekroun ◽  
Mostafa Nawdali ◽  
Zaitan Hicham

This study aimed to investigate the applicability of new low-cost activated carbons with a high surface area prepared by KOH chemical activation of jujube shells (denoted JSAC) as adsorbent of Chemical Organic Demand (COD) from wastewater.The prepared activated carbon is characterized by various physical-chemical methods to determine their morphological, textural and chemical characterization, including nitrogen adsorption-desorption isotherms, Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Boehm titration method and the pH of the point of zero charge (pHPZC).Then they were used as an adsorbent for the removal of COD from wastewater collected from Fez area. Adsorption equilibrium and kinetic data were determined and fitted to several adsorption isotherms and kinetics models, respectively. The results showed that the Langmuir isotherm fitted well the equilibrium data of COD on JSAC adsorbent; whereas, the kinetic data were best fitted by the pseudo-second-order model. This adsorbent showed the highest removal efficiency for COD (72%) and the grey colour of the wastewater (83%) for an optimum dose of 0.5 gJSAC. L-1. Results from the study showed that JSAC activated carbon could be utilized as an effective and less expensive adsorbent for the removal of COD in wastewater.


2019 ◽  
Author(s):  
Chem Int

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.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2951
Author(s):  
Mirosław Kwiatkowski ◽  
Jarosław Serafin ◽  
Andy M. Booth ◽  
Beata Michalkiewicz

This paper presents the results of a computer analysis of the effect of activation process temperature on the development of the microporous structure of activated carbon derived from the leaves of common polypody (Polypodium vulgare) via chemical activation with phosphoric acid (H3PO4) at activation temperatures of 700, 800, and 900 °C. An unconventional approach to porous structure analysis, using the new numerical clustering-based adsorption analysis (LBET) method together with the implemented unique gas state equation, was used in this study. The LBET method is based on unique mathematical models that take into account, in addition to surface heterogeneity, the possibility of molecule clusters branching and the geometric and energy limitations of adsorbate cluster formation. It enabled us to determine a set of parameters comprehensively and reliably describing the porous structure of carbon material on the basis of the determined adsorption isotherm. Porous structure analyses using the LBET method were based on nitrogen (N2), carbon dioxide (CO2), and methane (CH4) adsorption isotherms determined for individual activated carbon. The analyses carried out showed the highest CO2 adsorption capacity for activated carbon obtained was at an activation temperature of 900 °C, a value only slightly higher than that obtained for activated carbon prepared at 700 °C, but the values of geometrical parameters determined for these activated carbons showed significant differences. The results of the analyses obtained with the LBET method were also compared with the results of iodine number analysis and the results obtained with the Brunauer–Emmett–Teller (BET), Dubinin–Radushkevich (DR), and quenched solid density functional theory (QSDFT) methods, demonstrating their complementarity.


Author(s):  
Ali H. Jawad ◽  
Ahmed Saud Abdulhameed ◽  
Noor Nazihah Bahrudin ◽  
Nurul Nadiah Mohd Firdaus Hum ◽  
S. N. Surip ◽  
...  

Abstract In this work, sugarcane bagasse waste (SBW) was used as a lignocellulosic precursor to develop a high surface area activated carbon (AC) by thermal treatment of the SBW impregnated with KOH. This sugarcane bagasse waste activated carbon (SBWAC) was characterized by means of crystallinity, porosity, surface morphology and functional groups availability. The SBWAC exhibited Type I isotherm which corresponds to microporosity with high specific surface area of 709.3 m2/g and 6.6 nm of mean pore diameter. Further application of SBWAC as an adsorbent for methylene blue (MB) dye removal demonstrated that the adsorption process closely followed the pseudo-second order kinetic and Freundlich isotherm models. On the other hand, thermodynamic study revealed the endothermic nature and spontaneity of MB dye adsorption on SBWAC with high acquired adsorption capacity (136.5 mg/g). The MB dye adsorption onto SBWAC possibly involved electrostatic interaction, H-bonding and π-π interaction. This work demonstrates SBW as a potential lignocellulosic precursor to produce high surface area AC that can potentially remove more cationic dyes from the aqueous environment.


2017 ◽  
Vol 36 (3) ◽  
pp. 44-53
Author(s):  
G. D. Akpen ◽  
M. I. Aho ◽  
N. Baba

Activated carbon was prepared from the pods of Albizia saman for the purpose of converting the waste to wealth. The pods were thoroughly washed with water to remove any dirt, air- dried and cut into sizes of 2-4 cm. The prepared pods were then carbonised in a muffle furnace at temperatures of 4000C, 5000C, 6000C ,7000C and 8000C for 30 minutes. The same procedure was repeated for 60, 90, 120 and 150 minutes respectively. Activation was done using impregnationratios of 1:12, 1:6, 1:4, 1:3, and 1:2 respectively of ZnCl2 to carbonised Albizia saman pods by weight. The activated carbon was then dried in an oven at 1050C before crushing for sieve analysis. The following properties of the produced Albizia saman pod activated carbon (ASPAC) were determined: bulk density, carbon yield, surface area and ash, volatile matter and moisture contents. The highest surface area of 1479.29 m2/g was obtained at the optimum impregnation ratio, carbonization time and temperature of 1:6, 60 minutes and 5000C respectively. It was recommended that activated carbon should be prepared from Albizia saman pod with high potential for adsorption of pollutants given the high surface area obtained.Keywords: Albizia saman pod, activated carbon, carbonization, temperature, surface area


2020 ◽  
Vol 6 (4) ◽  
pp. 73 ◽  
Author(s):  
Rashma Chaudhary ◽  
Subrata Maji ◽  
Rekha Goswami Shrestha ◽  
Ram Lal Shrestha ◽  
Timila Shrestha ◽  
...  

Hierarchically porous activated carbon materials from agro-waste, Jackfruit seeds are prepared by a chemical activation method involving the treatment with zinc chloride (ZnCl2) at different temperatures (600–1000 °C). The electrochemical supercapacitance performances of the prepared materials were studied in an aqueous electrolyte (1 M sulfuric acid, H2SO4) in a three-electrode system. Jackfruit seed carbons display nanoporous structures consisting of both micro- and mesopore architectures and they are amorphous in nature and also contain oxygenated surface functional groups, as confirmed by powder X-ray diffraction (pXRD), Raman scattering, and Fourier-transformed infrared (FTIR) spectroscopy, respectively. The surface areas and pore volumes were found to be 1216.0 to 1340.4 m2·g−1 and 0.804 to 1.144 cm3·g−1, respectively, demonstrating the better surface textural properties compared to the commercial activated carbons. Due to the high surface area, large pore volume, and well developed hierarchical micro- and mesoporosity, the optimal sample achieved a high specific capacitance of 292.2 F·g−1 at 5 mV·s−1 and 261.3 F·g−1 at 1 A·g−1 followed by outstanding high rate capability. The electrode sustained 71.6% capacity retention at a high current density of 20 A·g−1. Furthermore, the electrode displayed exceptional cycling stability with small capacitance loss (0.6%) even after 10,000 charging–discharging cycles, suggesting that Jackfruit seed would have potential in low-cost and scalable production of nanoporous carbon materials for supercapacitors applications.


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