scholarly journals Fe and Ag supported on activated carbon as an effective adsorbent for 2,4-dichlorophenoxylacetic acid treatment: a theoretical study

2021 ◽  
Vol 63 (11) ◽  
pp. 2-6
Author(s):  
Thuy Hang Nguyen ◽  
◽  
Thi Be Pham ◽  
Thi Kim Giang Nguyen ◽  
Hoang Hao Nguyen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Mechanism ◽  
Physical Adsorption ◽  
Population Analysis ◽  
Tight Binding ◽  
Geometrical Parameters ◽  
Adsorption Ability ◽  
Metal Atoms ◽  
Vertical Electron Affinity ◽  
Poisson Boltzmann

Extended tight-binding quantum chemical method (GFN2-xTB) was performed to investigate the adsorption of 2,4-dichlorophenoxylacetic acid (2,4-D) on activated carbon (AC) and AC modified by Fe or Ag (AC-M). Electronic properties of the studied systems were estimated via vertical ionisation potential, vertical electron affinity, and global electrophilicity index. Adsorption energy, population analysis, and geometrical parameters were calculated to clarify the adsorption ability of AC and AC-M. The results indicated that the introduction of metal atoms to AC substantially enhanced the adsorption ability for 2,4-D. The adsorption mechanism changed from physical adsorption (on AC) to chemisorption (on AC-M). The influence of different solvents (water, methanol, and acetonitrile) on the adsorption process was studied via an Analytical linearized Poisson-Boltzmann algorithm.

Removal of Gas-Phase Elemental Mercury by Bromine-Impregnated Activated Carbon

2011 ◽  
Vol 356-360 ◽  
pp. 1660-1663 ◽  
Author(s):  
Jiang Wu ◽  
Jie He Chen ◽  
Shuai Bo Zhang ◽  
Ping He ◽  
Ji Hui Fang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Gas Phase ◽  
Removal Efficiency ◽  
Activated Carbons ◽  
Physical Adsorption ◽  
Fixed Bed ◽  
Elemental Mercury ◽  
Adsorption Ability ◽  
Bromine Concentration ◽  
Fixed Bed System

Br-impregnated activated carbon for gas-phase elemental mercury adsorption experiments were carried out at a fixed-bed system to get the suitable mass fraction of KBr impregnation solution. Hg removal efficiency of 1% wt KBr-ACs was 69.0%, while that of 10% wt KBr-ACs was 57.9%. Both of them were higher than that of the raw activated carbon, 42.2%. The removal efficiency of Hg0 was not proportional to bromine concentration. Under 80-180°C, Hg removal efficiency of 1% wt KBr-ACs were 68.3%-71.8%, and at 140°C it reached the highest due to the increasing chemical adsorption ability of the functional groups which was on the surfaces of activated carbons by impregnating. At 160°C, Hg removal efficiency was lower than that at 140°C due to desorption making physical adsorption decrease, so that the total adsorption decreased.

Study on Adsorption of Chromium in Wastewater by Diatomite

2014 ◽  
Vol 1004-1005 ◽  
pp. 983-989
Author(s):  
Kai Yong Zhang ◽  
Ling Huang
Keyword(s):  
Theoretical Basis ◽  
Adsorption Mechanism ◽  
Ph Value ◽  
Removal Rate ◽  
Physical Adsorption ◽  
Chromium Concentration ◽  
Adsorption Ability ◽  
Adsorption Time ◽  
Adsorption Removal ◽  
The Cost

Adsorption ability of chromium in wastewater by purified diatomite as the adsorbent material was studied. The influence of the diatomite dosage, adsorption time, chromium concentration, pH value and reaction temperature to chromium removal rate was got. The results show that under the condition of the diatomite dosage of 9.0g, adsorption time of 90 min, chromium concentration in wastewater of 5mg/L, wastewater pH of 6, and temperature of 30°C, diatomite adsorption removal rate to hexavalent chromium can reach 91.6%. The main adsorption mechanism is the combination of physical adsorption and chemical adsorption, and the latter is dominant. The cost of diatomite as adsorbent is low, and a good removal rate of chromium can be reached, which provides a solid theoretical basis for the removal of chromium in wastewater.

Adsorption mechanism of NH3, NO, and O2 molecules over FexOy/AC catalyst surface: a DFT-D3 study

2021 ◽  
Author(s):  
Chaoyue Xie ◽  
Yunlan Sun ◽  
Baozhong Zhu ◽  
Weiyi Song ◽  
Minggao Xu
Keyword(s):  
Activated Carbon ◽  
Adsorption Mechanism ◽  
Catalyst Surface ◽  
Specific Adsorption ◽  
Adsorption Mechanisms ◽  
Iron Based ◽  
Iron Based Catalysts ◽  
Supported Iron ◽  
Denox Efficiency

Activated carbon-supported iron-based catalysts (FexOy/AC) show excellent deNOx efficiency. However, the specific adsorption mechanisms of NH3, NO, and O2 molecules on their surfaces are still unknown. In this study, the...

scholarly journals Computer Analysis of the Effect of Activation Temperature on the Microporous Structure Development of Activated Carbon Derived from Common Polypody

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2951
Author(s):  
Mirosław Kwiatkowski ◽  
Jarosław Serafin ◽  
Andy M. Booth ◽  
Beata Michalkiewicz
Keyword(s):  
Activated Carbon ◽  
Porous Structure ◽  
Computer Analysis ◽  
Density Functional ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Geometrical Parameters ◽  
Activation Process ◽  
Microporous Structure ◽  
Activation Temperature

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.

scholarly journals Study on Adsorption Properties of Modified Corn Cob Activated Carbon for Mercury Ion

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4483
Author(s):  
Yuyingnan Liu ◽  
Xinrui Xu ◽  
Bin Qu ◽  
Xiaofeng Liu ◽  
Weiming Yi ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Adsorption Process ◽  
Physical Adsorption ◽  
Raw Material ◽  
Order Kinetic ◽  
Mercury Ions ◽  
Corn Cob ◽  
Adsorption Time ◽  
X Ray

In this study, corn cob was used as raw material and modified methods employing KOH and KMnO4 were used to prepare activated carbon with high adsorption capacity for mercury ions. Experiments on the effects of different influencing factors on the adsorption of mercury ions were undertaken. The results showed that when modified with KOH, the optimal adsorption time was 120 min, the optimum pH was 4; when modified with KMnO4, the optimal adsorption time was 60 min, the optimal pH was 3, and the optimal amount of adsorbent and the initial concentration were both 0.40 g/L and 100 mg/L under both modified conditions. The adsorption process conforms to the pseudo-second-order kinetic model and Langmuir model. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Zeta potential characterization results showed that the adsorption process is mainly physical adsorption, surface complexation and ion exchange.

Marvelous oleophillic adsorption ability of SiO2/activated carbon and GO composite nanostructure using polyurethane for rapid oil spill cleanup

2021 ◽  
Vol 11 (4) ◽  
pp. 1211-1223
Author(s):  
Attika Malik ◽  
Shamaila Sajjad ◽  
Sajjad Ahmed Khan Leghari ◽  
Youmna Naz ◽  
Maria Masood ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Oil Spill ◽  
Adsorption Ability ◽  
Oil Spill Cleanup

The adsorption mechanism and rapid screening of activated carbon for 2-methylisoborneol adsorption

Carbon ◽  
2013 ◽  
Vol 60 ◽  
pp. 567
Author(s):  
Takayuki Watanabe ◽  
Yoshimasa Amano ◽  
Motoi Machida
Keyword(s):  
Activated Carbon ◽  
Adsorption Mechanism ◽  
Rapid Screening

scholarly journals Theoretical and Experimental Studies for Inhibition Potentials of Imidazolidine 4-One and Oxazolidine 5-One Derivatives for the Corrosion of Carbon Steel in Sea Water

2020 ◽  
pp. 2776-2796
Author(s):  
Rehab M Kubba ◽  
Nada M. Al-Joborry ◽  
Naeemah J. Al-lami
Keyword(s):  
Carbon Steel ◽  
Density Functional ◽  
Sea Water ◽  
Physical Adsorption ◽  
Population Analysis ◽  
Experimental Studies ◽  
Experimental Methods ◽  
Equilibrium Geometry ◽  
Quantum Mechanical Method ◽  
Derivatives Of

Two derivatives of Iimidazolidin 4-one (IMID4) and Oxazolidin 5-one (OXAZ5), were investigated as corrosion inhibitors of corrosion carbon steel in sea water by employing the theoretical and experimental methods. The results revealed that they inhibit the corrosion process and their %IE followed the order: IMID4 (89.093%) > OXAZ5 (80.179%). The %IE obtained via theoretical and experimental methods were in a good agreement with each other. The thermodynamic parameters obtained by potentiometric polarization measurements have supported a physical adsorption mechanism which followed Langmuir adsorption isotherm. Quantum mechanical method of Density Functional Theory (DFT) of B3LYP with a level of 6-311++G (2d, 2p) were used to calculate the geometrical structure, physical properties and inhibition efficiency parameters, in vacuum and two solvents (DMSO and H2O), all calculated at the equilibrium geometry, and correlated with the experimental %IE. The local reactivity has been studied through Mulliken charges population analysis. The morphology of the surface changes of carbon steel were studied using SEM and AFM techniques.

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