Competitive adsorption of ofloxacin enantiomers to goethite: experiments and modelling

2021 ◽  
Author(s):  
Xiaopeng Qin ◽  
Xiaofei Zhong ◽  
Ping Du ◽  
Juan Chen ◽  
Junfeng Jia ◽  
...  
Keyword(s):  
Competitive Adsorption ◽  
Ofloxacin Enantiomers

PHYTOACCUMULATION, COMPETITIVE ADSORPTION AND EVALUATION OF CHELATORS-METAL INTERACTION IN LETTUCE PLANT

2014 ◽  
Vol 13 (10) ◽  
pp. 2583-2592 ◽  
Author(s):  
Beenish Saba ◽  
Audil Rashid ◽  
Tariq Mahmood ◽  
Faisal Mehmood ◽  
Azeem Khalid ◽  
...  
Keyword(s):  
Competitive Adsorption ◽  
Lettuce Plant ◽  
Metal Interaction

Competitive adsorption of organic solvents using modified and unmodified calcium bentonite clay mineral

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Organic Solvents ◽  
Competitive Adsorption ◽  
Correlation Factor ◽  
Isotherm Model ◽  
Isotherm Models ◽  
High Concentration ◽  
Dual Purpose ◽  
Calcium Bentonite

Dodecyltrimethylammonium bromide (DTAB)–modified and unmodified calcium bentonite were both used for the competitive adsorption of aromatics (xylene, ethylbenzene and toluene) and petroleum products (gasoline, dual purpose kerosene and diesel) from their aqueous solution. Infrared spectroscopy (IR) and expansion tests (adsorption capacity and Foster swelling) measurement were performed in order to evaluate the performance of the adsorbents. The Foster swelling index and adsorption capacity of the DTAB modified calcium bentonite in the organic solvents follow the trend: xylene > ethylbenzene > toluene > gasoline > dual purpose kerosene (DPK) > diesel > water. However, the adsorption capacity of the adsorbent in diesel outweighed the adsorption capacity in DPK at high concentration of DTAB indicating that diesel has higher affinity for high DTAB concentration than DPK. The percentage removal of the solvent is directly proportional to the concentration of DTAB used in modifying the bentonite as well as the contact time between the adsorbent and the solvent, hence modified calcium bentonite adsorbed a higher percentage of organic solvents than the unmodified calcium bentonite. The adsorption characteristics of both adsorbents improved remarkably after proper agitation of the organic solvents, the unmodified calcium bentonite however adsorbed more water than the modified bentonite. Data obtained from adsorption isotherm models confirms that Freundlich adsorption isotherm model was favored more than Langmuir adsorption isotherm model with the correlation factor (R2) of the former tending more towards unity. The adsorption of ethylbenzene using DTAB modified and unmodified calcium bentonites follow a pseudo second order kinetics mechanism, suggesting that the rate determining step of adsorption involves both the adsorbent and the organic solvent.

Synergistic and Competitive Adsorption of Methylene Blue and Rhodamine B on Core-shell Magnetic Manganese Dioxide Nanocomposites

2017 ◽  
Vol 13 (6) ◽  
Author(s):  
Linshan Wang ◽  
Cholhwan Kim ◽  
Xinyue Zhang ◽  
Carlos Fernandez ◽  
Ting Sun ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Manganese Dioxide ◽  
Rhodamine B ◽  
Competitive Adsorption ◽  
Core Shell

Utilisation of Biomass and Hybrid Biochar from Elephant Grass and Low Density Polyethylene for the Competitive Adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) from Aqueous Media

2020 ◽  
Vol 13 ◽  
Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Removal Efficiency ◽  
Contact Time ◽  
Competitive Adsorption ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Polluted Water ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Elephant Grass

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.

Influence of competitive adsorption of water and fuel on the activity of anodes in fuel cells

1971 ◽  
Vol 36 (2) ◽  
pp. 928-931 ◽  
Author(s):  
G. Schulz-Ekloff ◽  
D. Baresel ◽  
J. Heidemeyer
Keyword(s):  
Fuel Cells ◽  
Competitive Adsorption ◽  
Adsorption Of Water

The competitive adsorption mechanism of CO2, H2O and O2 on a solid amine adsorbent

2021 ◽  
pp. 129007
Author(s):  
Yanxia Wang ◽  
Xiude Hu ◽  
Tuo Guo ◽  
Wengang Tian ◽  
Jian Hao ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Competitive Adsorption

scholarly journals Molecular simulation of gases competitive adsorption in lignite and analysis of original CO desorption

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jing Zhang ◽  
Jiren Wang ◽  
Chunhua Zhang ◽  
Zongxiang Li ◽  
Jinchao Zhu ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Molecular Simulation ◽  
Competitive Adsorption ◽  
Air Leakage ◽  
Adsorption Characteristics ◽  
Adsorption Sites ◽  
Simulation Based ◽  
Lignite Coal ◽  
Model C ◽  
Grand Canonical

AbstractTo study the adsorption characteristics of CO, CO2, N2, O2, and their binary-components in lignite coal, reveal the influence of CO2 or N2 injection and air leakage on the desorption of CO in goafs, a lignite model (C206H206N2O44) was established, and the supercell structure was optimized under temperatures of 288.15–318.15 K for molecular simulation. Based on molecular dynamics, the Grand Canonical Monte Carlo method was used to simulate the adsorption characteristics and the Langmuir equation was used to fit the adsorption isotherms of gases. The results show that for single-components, the order of adsorption capacity is CO2 > CO > O2 > N2. For binary-components, the competitive adsorption capacities of CO2 and CO are approximate. In the low-pressure zone, the competitive adsorption capacity of CO2 is stronger than that of CO, and the CO is stronger than N2 or O2. From the simulation, it can be seen that CO2, N2 or O2 will occupy adsorption sites, causing CO desorption. Therefore, to prevent the desorption of the original CO in the goaf, it is not suitable to use CO2 or N2 injection for fire prevention, and the air leakage at the working faces need to be controlled.

Competitive adsorption of phenol and toluene onto silica-supported transition metal clusters for biofuel purification

2021 ◽  
Author(s):  
Saber Gueddida ◽  
Michael Badawi ◽  
Tejraj Aminabhavi ◽  
Sébastien Lebègue
Keyword(s):  
Transition Metal ◽  
Competitive Adsorption ◽  
Metal Clusters ◽  
Hydrocarbon Fuel ◽  
Energy Performance ◽  
Transition Metal Clusters ◽  
Gas Emissions ◽  
Toxic Gas

Biomass-based renewable hydrocarbon fuel is a complex mix that contains many oxygenating substances, in particular phenolics, which leads to adverse consequences such as reduced engine energy performance and increased toxic gas emissions.

Competitive adsorption of multicomponent volatile organic compounds on biochar

Chemosphere ◽  
2021 ◽  
pp. 131288
Author(s):  
Hamid Rajabi ◽  
Mojgan Hadi Mosleh ◽  
Tirto Prakoso ◽  
Negin Ghaemi ◽  
Parthasarathi Mandal ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Competitive Adsorption ◽  
Volatile Organic

Effect Of Phosphorus On Ge/Si(001) Island Formation

2002 ◽  
Vol 737 ◽  
Author(s):  
Theodore I. Kamins ◽  
Gilberto Medeiros-Ribeiro ◽  
Douglas A. A. Ohlberg ◽  
R. Stanley Williams
Keyword(s):  
Deposition Rate ◽  
Strain Energy ◽  
Competitive Adsorption ◽  
Lattice Mismatch ◽  
Three Dimensional ◽  
Deposition Process ◽  
Thin Layers ◽  
Island Size ◽  
Partial Pressures ◽  
Intermediate Size

ABSTRACTWhen Ge is deposited epitaxially on Si, the strain energy from the lattice mismatch causes the Ge in layers thicker than about four monolayers to form distinctive, three-dimensional islands. The shape of the islands is determined by the energies of the surface facets, facet edges, and interfaces. When phosphorus is added during the deposition, the surface energies change, modifying the island shapes and sizes, as well as the deposition process. When phosphine is introduced to the germane/hydrogen ambient during Ge deposition, the deposition rate decreases because of competitive adsorption. The steady-state deposition rate is not reached for thin layers. The deposited, doped layers contain three different island shapes, as do undoped layers; however, the island size for each shape is smaller for the doped layers than for the corresponding undoped layers. The intermediate-size islands are the most significant; the intermediate-size doped islands are of the same family as the undoped, multifaceted “dome” structures, but are considerably smaller. The largest doped islands appear to be related to the defective “superdomes” discussed for undoped islands. The distribution between the different island shapes depends on the phosphine partial pressure. At higher partial pressures, the smaller structures are absent. Phosphorus appears to act as a mild surfactant, suppressing small islands.

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