scholarly journals Microwave Synthesis, Characterization and Perspectives of Wood Pencil-Derived Carbon

2022 ◽  
Vol 12 (1) ◽  
pp. 410
Author(s):  
Nikolaos Chalmpes ◽  
Georgios Asimakopoulos ◽  
Maria Baikousi ◽  
Constantinos E. Salmas ◽  
Dimitrios Moschovas ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Surface Area ◽  
Microwave Synthesis ◽  
Chemical Activation ◽  
Added Value ◽  
Maximum Adsorption Capacity ◽  
Carbon Nanosheets ◽  
Process Stage ◽  
Domestic Microwave Oven ◽  
Original Length

More than 14 billion pencils are manufactured and used globally every year. On average, a pencil is discarded after 60% of its original length has been depleted. In the present work we propose a simple and affordable way of converting this non-neglectable amount of waste into added value carbon product. In particular, we demonstrate the microwave synthesis of carbon from the wood pencil with and without chemical activation. This could be a process stage before the final recycling of the expensive graphite core. In the latter case, irradiation of the wood pencil in a domestic microwave oven heats up the pencil’s graphite core, thus inducing carbonization of its wood casing. The carbonized product consists of amorphous carbon nanosheets having relatively low surface area. However, if the wood pencil is soaked in 50% KOH aqueous solution prior to microwave irradiation, a significantly higher surface area of carbon is obtained, consisting of irregular-shaped porous particles. Consequently, the obtained carbon can easily decolorize a methylene blue aqueous solution, can be used to make pocket warmers or gunpowder, and lastly, serves as an excellent adsorbent towards Cr(VI) removal from water, showing a maximum adsorption capacity of 70–75 mg/g within 24 h at 23 °C, pH = 3.

scholarly journals Utilization of Charred Water Hyacinth (Jalkumvi) as Biosorbent for Removal of Ca(II) Ion from Aqueous Solution

2021 ◽  
Vol 42 (1) ◽  
pp. 107-114
Author(s):  
Arun Bhujel ◽  
Krishna Wagle ◽  
Bishow Regmi ◽  
Bibek Sapkota ◽  
Bhoj Raj Poudel ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Water Hyacinth ◽  
Chemical Activation ◽  
Freundlich Isotherm ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Adsorbent Surface ◽  
Sem Micrograph ◽  
Pseudo Second Order ◽  
Efficient Alternative

A promising adsorbent, charred water hyacinth (CWH) for the removal of Ca(II) from the aqueous solution was explored by heat treatment of water hyacinth followed by chemical activation with acidified zinc chloride (ZnCl2). The adsorbent was characterized using scanning electron microscopy (SEM) and electron dispersive X-ray (EDX) spectroscopy. Batch adsorption techniques were conducted for Ca(II) adsorption to assess the adsorption isotherm, effect of pH, contact time, initial Ca(II) concentration, adsorbent doses, and adsorption kinetics. The SEM micrograph illustrates the rough and irregular surface morphology and EDX spectra confirm the successful adsorption of Ca(II) on the adsorbent surface. The equilibrium adsorption data better fitted to the Freundlich isotherm model having a maximum adsorption capacity (qmax) of 319.75 mg/g. The highest percentage of adsorption was found at pH 1.5. The adsorption of Ca(II) by CWH decreased at the higher metal concentration and lower adsorbent doses. The adsorption of Ca(II) ions onto CWH followed the pseudo-second-order kinetics model. . Overall, these results suggested that the as-prepared CWH can be used as an eco-friendly, economical and efficient alternative for the removal of Ca(II)  from the aqueous solution.

Streptococcus vestibularis atypical infectious keratits after intracorneal ring segment implantation

2021 ◽  
pp. 112067212110147
Author(s):  
María Isabel Soler Sanchis ◽  
Lidia Remolí Sargues ◽  
Ramón Calvo Andrés ◽  
Lucía Mata Moret ◽  
Clara Monferrer Adsuara ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Surface Area ◽  
Adsorption Process ◽  
Activated Carbons ◽  
Good Description ◽  
Physical Adsorption ◽  
Maximum Adsorption Capacity ◽  
Kinetics Parameters ◽  
X Ray ◽  
Bet Analysis

This study investigates the adsorption behavior of methyl orange (MO) by magnetic activated carbons (MACs) with different ratios of AC:Magnetite from aqueous solution. Batch experiments for MO adsorption were carried out for evaluating the thermodynamics and kinetics parameters onto the MACs adsorbents. Variables such as pH, initial concentration of the dye, contact time, and temperature have been analyzed. The physicochemical characteristics of MACs were analyzed by scanning electron microscopy (SEM), surface area analyzer (BET), and X-ray power diffraction. The results of SEM and BET analysis showed that MACs adsorbents present a porous structure and large surface area, suitable conditions for the adsorption process. The X-ray diffraction patterns of MACs revealed that the adsorbents possess magnetite as magnetic material. Adsorption kinetic studies carried out onto MACs showed that the pseudo-second order model provides a good description of the kinetic process. The adsorption equilibrium results were well adjusted to the Langmuir isotherm, showing that the maximum adsorption capacity was for MACs with a ratio 3:1 and 2:1 AC/magnetite. Thermodynamic analysis declare that the adsorption process was established as spontaneous, endothermic and physical adsorption in nature. The results of the present study indicated that MACs adsorbents can be used successfully for eliminating MO from aqueous solution.

scholarly journals Advantages of the Incorporation of Luffa-Based Activated Carbon to Titania for Improving the Removal of Methylene Blue from Aqueous Solution

2021 ◽  
Vol 11 (16) ◽  
pp. 7607
Author(s):  
Souad Boumad ◽  
Antonia Infantes-Molina ◽  
Isabel Barroso-Martín ◽  
Elisa Moretti ◽  
Enrique Rodríguez-Castellón ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Activated Carbon ◽  
Surface Area ◽  
Uv Light ◽  
Physical Adsorption ◽  
Chemical Activation ◽  
Tio2 Photocatalysts ◽  
Degussa P25

This research aims to study the possible improvement of methylene blue (MB) removal from aqueous solution by hybrid adsorbent-catalysts (AdsCats) prepared through the incorporation of activated carbon derived from Luffa cylindrica fibers (LAC) to TiO2 photocatalysts. LAC with a specific surface area of 1170 m2/g was prepared by chemical activation with phosphoric acid at 500 °C. TiO2/LAC composites with 70 and 90 wt.% Degussa P25 titania content were prepared. The materials were characterized by N2 physical adsorption, XRD, FTIR, and XPS. The AdsCats displayed a very good dispersion of TiO2 over LAC, a surface area of close to 200 or 400 m2/g, depending on the composition, and high crystallinity, showing the presence of anatase and rutile phases. MB removal was studied in two different scenarios: under UV-light after reaching adsorption equilibrium, and under UV-light once the liquid effluent and the AdsCats were in contact. The MB removal by LAC has proved to be very efficient, highlighting the predominant role of adsorption over photodegradation. The prepared AdsCats have also been compared with their components. The results showed that TiLAC hybrids have superior photocatalytic performance than P25, showing TiLAC-7/3 90% MB removal with respect to the initial concentration just after 30 min of UV light irradiation for both studied scenarios.

scholarly journals Thermodynamics and Kinetic Studies for the Adsorption Process of Methyl Orange by Magnetic Activated Carbons

2021 ◽  
Vol 14 ◽  
pp. 117862212110133
Author(s):  
Ana Karen Cordova Estrada ◽  
Felipe Cordova Lozano ◽  
René Alejandro Lara Díaz
Keyword(s):  
Aqueous Solution ◽  
Methyl Orange ◽  
Surface Area ◽  
Adsorption Process ◽  
Activated Carbons ◽  
Good Description ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Bet Analysis

This study investigates the adsorption behavior of methyl orange (MO) by magnetic activated carbons (MACs) with different ratios of AC: Magnetite from aqueous solution. Batch experiments for MO adsorption were carried out for evaluating the thermodynamics and kinetics parameters onto the MAC adsorbents. Variables such as pH, initial concentration of the dye, contact time, and temperature have been analyzed. The physicochemical characteristics of MACs were analyzed by scanning electron microscopy (SEM), surface area analyzer (BET), and X-ray power diffraction. The results of SEM and BET analysis showed that MAC adsorbents present a porous structure and large surface area, suitable conditions for the adsorption process. The X-ray diffraction patterns of MACs revealed that the adsorbents possess magnetite as magnetic material. Adsorption kinetic studies carried out onto MACs showed that the pseudo-second-order model provides a good description of the kinetic process. The adsorption equilibrium results were well adjusted to the Langmuir isotherm, showing that the maximum adsorption capacity was for MACs with a ratio 3:1 and 2:1 AC/magnetite. Thermodynamic analysis declares that the adsorption process was established as spontaneous, endothermic, and physical adsorption in nature. The results of the this study indicated that MAC adsorbents can be used successfully for eliminating MO from aqueous solution.

scholarly journals Removal of Cr(VI) from aqueous solution by biochar derived from rice husk

2021 ◽  
Vol 6 (1) ◽  
pp. 11-17
Author(s):  
Risfidian Mohadi ◽  
Neza Rahayu Palapa ◽  
Tarmizi Taher ◽  
Patimah Mega Syah Bahar Nur Siregar ◽  
Normah ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Surface Area ◽  
Rice Husk ◽  
Order Reaction ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Rice Husks ◽  
Xrd Pattern ◽  
Adsorption Study ◽  
Good Potential

In this work, biochar produced from Indonesian rice husks. Then used as adsorbent of Cr(VI) in aqueous solution. The XRD pattern of biochar showed the characterization pattern at 23º (002) reflection, appearance of silicate oxide, and the carbon vibrations. The surface area and SEM morphologies confirmed that after pyrolysis treatment the surface of rice husk has changed. The surface area of biochar increased after thermal treatment. The adsorption study of Cr(VI) by biochar demonstrate 2nd-order reaction, and Langmuir isotherm models. The maximum adsorption capacity of biochar derived rice husk to adsorb Cr(VI) is 161.290 mg/g, and biochar showed the good potential as reuseable adsorbent to remove heavy metal in aqueous solution.

scholarly journals Effect of activated carbons from rubber seed shell on Crystal Violet removal

2020 ◽  
Vol 22 (1) ◽  
pp. 43-54 ◽  
Author(s):  
B. Anegbe ◽  
R.C. Emeribe ◽  
J.M. Okuo
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Crystal Violet ◽  
Optimum Concentration ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Rubber Seed ◽  
Adsorbent Dose

Dyes are complex organic compounds which are used by various industries to add colour to their products. Water bodies are polluted when these industries dispose their effluents to the environment. In this study, powdered activated carbon was prepared from rubber seed shells (RSS) and was employed in the removal of crystal violet from aqueous solution. The rubber seed shell was first activated using ammonium chloride, shared into two portions and was carbonized at 500 and 300o C respectively. They were characterized in terms of bulk density, ash and moisture contents, surface area and IR Spectroscopy. Batch adsorption process which involved the use of these rubber seed shells was employed in the removal of crystal violet from aqueous solution. The effect of contact time, adsorbent dose, pH and dye concentration were investigated. The results showed that o maximum adsorption capacity of 500 C carbonized rubber seed shell was 97.93 % at 75 mins. The adsorbent dose, pH and optimum concentration were respectively 5.0 g, 10 and 10 mg/l. The maximum adsorption  capacity of 300o C carbonized rubber seed shell was 96.73 % at 30 mins with an adsorbent dose of 5.0 g; pH of 10 and optimum concentration of 10 mg/l. The experimental data obtained were fitted into Freundlich,Langmuir, Temkin and Frumkin adsorption isotherms and was found to fit into the four isotherms. However,  the rubber seed shell carbonized at 500o C was found to be more effective in the removal of crystal violet from o aqueous solution than that carbonized at 300o C. This might probably be due to the larger surface area. Keywords: Activated Carbon, Rubber Seed Shell and Crystal Violet

A corn stalk-derived porous carbonaceous adsorbent for adsorption of ionic liquids from aqueous solution

RSC Advances ◽  
2016 ◽  
Vol 6 (39) ◽  
pp. 32505-32513 ◽  
Author(s):  
Yu Wang ◽  
Feng Shen ◽  
Xinhua Qi
Keyword(s):  
Aqueous Solution ◽  
Ionic Liquids ◽  
Surface Area ◽  
Chemical Activation ◽  
High Surface ◽  
High Surface Area ◽  
Carbonaceous Material ◽  
Hydrothermal Carbonization ◽  
Corn Stalk ◽  
Carbonaceous Adsorbent

Corn stalks were used to prepare a porous carbonaceous material with a high surface area of 2442 m2 g−1 by the hydrothermal carbonization of corn stalks followed by chemical activation.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

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