Adsorption of Lead (II) in Liquid-Solid Interfaces on Natural and Modified Hydroxyapatite

2016 ◽  
Vol 721 ◽  
pp. 117-122 ◽  
Author(s):  
Samia Benhammadi ◽  
Andrei Shishkin ◽  
Abdelkader Iddou ◽  
Hakim Aguedal ◽  
Louis Charles de Menorval
Keyword(s):  
Heavy Metals ◽  
Lactic Acid ◽  
Extraction Method ◽  
Room Temperature ◽  
Adsorption Model ◽  
Initial Concentration ◽  
Langmuir Adsorption ◽  
Langmuir Adsorption Model ◽  
Adsorption Capacities ◽  
Different Temperatures

The removal of lead from aqueous solutions was studied using the liquid-solid extraction method. The solids used are the crude phosphocalcic hydroxapatite [Ca10(PO4)6(OH)2] (HAPc), and phosphocalcic hydroxapatite treated with 5 % lactic acid solution (HAPal). The extraction results showed the influence of the initial concentration of Pb (II) and temperature of the suspensions. The maximum adsorption capacities of each material (HAPc and HAPal) were obtained with the application of Langmuir adsorption model. The most important quantity was founded as 41,84mg/g for HAPal. Isotherms established at different temperatures showed that this parameter affects greatly the adsorption of Pb (II) on both adsorbents. The best results were obtained at room temperature (25°C) compared with those recorded at 50°C.Finally, the results of this study allow us to note that the hydroxiapatite material can be as good extractant solid, for heavy metals, especially when it is modified with lactic acid.

scholarly journals Thermodynamics of adsorption of food colours

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Adebayo Akinbulu ◽  
Toafeek Ogunbayo
Keyword(s):  
Molecular Size ◽  
Entropy Change ◽  
Brilliant Blue ◽  
Adsorption Model ◽  
Equilibrium Studies ◽  
Thermodynamics Of Adsorption ◽  
Langmuir Adsorption ◽  
Langmuir Adsorption Model ◽  
Different Temperatures ◽  
Food Colours

Thermodynamics of adsorption of two synthetic food colours, Tartrazine and Brilliant blue, was investigated. The adsorbent used was activated carbon, produced from saw dust waste. For each of the food colours, equilibrium studies were carried out at different temperatures (308 K, 318 K, 328 K and 338 K). The Langmuir adsorption model was employed for equilibrium studies. Amount of colour adsorbed per gram of adsorbent, at equilibrium, was influenced by molecular size of adsorbate and temperature. Adsorption at the tartrazine-adsorbent interface was exothermic, while that at the brilliant blue-adsorbent interface was endothermic. Adsorption of tartrazine was associated with a negative entropy change, while there was increased degree of disorderliness at the brilliant blue-adsorbent interface. Each of the adsorbate-adsorbent systems was associated with positive change in Gibbs free energy, within the range of temperature employed in this work.

Adsorption of Ni2+ and Cu2+ from Aqueous Solution by Polyethylenimine Impregnation of Metal–Organic Frameworks

NANO ◽  
2020 ◽  
Vol 15 (03) ◽  
pp. 2050029 ◽  
Author(s):  
Dan Wang ◽  
Xinfeng Xiao ◽  
Bo Han ◽  
Weiming Ni ◽  
Yu Gao ◽  
...  
Keyword(s):  
Order Kinetic ◽  
Adsorption Model ◽  
Elution Time ◽  
Langmuir Adsorption ◽  
Langmuir Adsorption Model ◽  
Adsorption Capacities ◽  
Order Kinetic Model ◽  
Metal Organic ◽  
Pseudo Second Order

A series of UiO-66-PEI materials were obtained by impregnating UiO-66 with different amounts of polyethylenimine (PEI) with UiO-66 as the basic skeleton material. The materials were used as adsorbents to remove Ni[Formula: see text] and Cu[Formula: see text] from water. The prepared UiO-66-PEI-30 had good adsorption capacity on Ni[Formula: see text] and Cu[Formula: see text] at 30% PEI. The adsorption of Ni[Formula: see text] and Cu[Formula: see text] with UiO-66-PEI-30 was further studied. The role of eluent types, elution time, concentration and volume on the effect of Cu[Formula: see text] elution was investigated. The adsorption of Ni[Formula: see text] and Cu[Formula: see text] by UiO-66-PEI-30 followed the pseudo-second-order kinetic model and Langmuir adsorption model. The maximum adsorption capacities obtained by Langmuir fitting for Ni[Formula: see text] and Cu[Formula: see text] were 11.54[Formula: see text]mg[Formula: see text]g[Formula: see text] and 24.87[Formula: see text]mg[Formula: see text]g[Formula: see text], respectively. After four desorption/adsorption experiments, UiO-66-PEI-30 still showed good adsorption performance. UiO-66 impregnated with PEI was an adsorbent with adsorption potential.

scholarly journals Combined Influence of Low-Grade Metakaolins and Natural Zeolite on Compressive Strength and Heavy Metal Adsorption of Geopolymers

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 486
Author(s):  
Alcina Johnson Sudagar ◽  
Slávka Andrejkovičová ◽  
Fernando Rocha ◽  
Carla Patinha ◽  
Maria R. Soares ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Compressive Strength ◽  
Natural Zeolite ◽  
Metal Adsorption ◽  
Low Grade ◽  
Heavy Metal Adsorption ◽  
Adsorption Model ◽  
X Ray ◽  
Adsorption Capacities

Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) regions of Portugal were used as the aluminosilicate source to compare their effect on the compressive strength and heavy metal adsorption of geopolymers. Natural zeolite, an inexpensive, efficient adsorbent, was used as an additive in formulations to enhance geopolymers’ adsorption capacities and reduce MK utilization’s environmental footprint. Geopolymers were synthesized with the replacement of MK by zeolite up to 75 wt.% (A25, B25—25% MK 75% zeolite; A50, B50—50% MK 50% zeolite; A75, B75—75% MK 25% zeolite; A100, B100—100% MK). The molar ratios of SiO2/Al2O3 and Na2O/Al2O3 were kept at 1 to reduce the sodium silicate and sodium hydroxide environmental impact. Geopolymers’ crystallography was identified using X-ray diffraction analysis. The surface morphology was observed by scanning electron microscopy to understand the effect of zeolite incorporation. Chemical analysis using X-ray fluorescence spectroscopy and energy dispersive X-ray spectroscopy yielded information about the geopolymers’ Si/Al ratio. Compressive strength values of geopolymers obtained after 1, 14, and 28 days of curing indicate high strengths of geopolymers with 100% MK (A100—15.4 MPa; B100—32.46 MPa). Therefore, zeolite did not aid in the improvement of the compressive strength of both MK-based geopolymers. The heavy metal (Cd2+, Cr3+, Cu2+, Pb2+, and Zn2+) adsorption tests exhibit relatively higher adsorption capacities of Barqueiros MK-based geopolymers for all the heavy metals except Cd2+. Moreover, zeolite positively influenced divalent cations’ adsorption on the geopolymers produced from Barqueiros MK as B75 exhibits the highest adsorption capacities, but such an influence is not observed for Alvarães MK-based geopolymers. The general trend of adsorption of the heavy metals of both MK-based geopolymers is Pb2+ > Cd2+ > Cu2+ > Zn2+ > Cr3+ when fitted by the Langmuir isotherm adsorption model. The MK and zeolite characteristics influence geopolymers’ structure, strength, and adsorption capacities.

scholarly journals The Effect of Deposition Time on the Surface Coverage of Sublimation Deposited Solid-Phase Glycine and Proline Molecules Measured by Scanning Tunneling Microscopy

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 2962
Author(s):  
Young-Sang Youn
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Room Temperature ◽  
Deposition Time ◽  
Surface Coverage ◽  
Solid Phase ◽  
Scanning Tunneling ◽  
Adsorption Model ◽  
Tunneling Microscopy ◽  
Langmuir Adsorption ◽  
Stm Images

The effect of deposition time on the surface coverage of sublimation deposited solid-phase glycine and proline molecules onto a Ge(100) surface was studied at room temperature using scanning tunneling microscopy (STM). The STM images obtained at various coverages of glycine and proline adsorbed on the Ge(100) surface showed that (i) the adsorption rate for both molecules gradually decreased with increasing deposition time, obeying the Langmuir adsorption model, and (ii) the coverage of glycine on the Ge(100) surface is higher than that of proline under the same deposition conditions, which may be due to the differences in their molecular weight or molecular sticking probability.

scholarly journals Determination of the absolute CH4 adsorption using simplified local density theory and comparison with the modified Langmuir adsorption model

RSC Advances ◽  
2018 ◽  
Vol 8 (72) ◽  
pp. 41509-41516
Author(s):  
Yeyu Zhang ◽  
Shaonan Zhang ◽  
Zhicheng Wang ◽  
Hucheng Deng ◽  
Minghui Qi ◽  
...  
Keyword(s):  
Shale Gas ◽  
Local Density ◽  
Gas Storage ◽  
Adsorption Model ◽  
Gas Reservoirs ◽  
Methane Recovery ◽  
Langmuir Adsorption ◽  
Langmuir Adsorption Model ◽  
Ch4 Adsorption

Accurately determining the adsorbed amount of CH4 on shale is significant for understanding the mechanisms of shale gas storage and shale methane recovery from shale gas reservoirs.

Investigation of Ultrasonic Effects in Cotton Dyeing Processing

2013 ◽  
Vol 787 ◽  
pp. 138-142 ◽  
Author(s):  
De Shuai Sun ◽  
Long Fang ◽  
Tao Liu
Keyword(s):  
Cotton Fiber ◽  
Ultrasound Irradiation ◽  
Cotton Fabrics ◽  
Dye Uptake ◽  
Adsorption Model ◽  
Langmuir Adsorption ◽  
Langmuir Adsorption Model ◽  
Dyeing Process ◽  
Direct Dye ◽  
Ultrasound Dyeing

Ultrasound can promote the dye-uptake in the dyeing process. The effects of ultrasound on the fiber, dye and dyeing system were investigated by dyeing cotton fabrics with a direct dye. The dye exhaustion exceeded 80% in 30 minutes with the assistant of ultrasound. Langmuir adsorption model could descript the ultrasound dyeing process of direct dye. The area of fiber accessibility of cotton fiber increased 1.68 times under the action of ultrasound. The absorbance of direct dye solution increased remarkably in the first 10 minutes of ultrasound irradiation. Ultrasound accelerated the diffusion of dye on cotton fiber, and then the diffusion coefficient increased 46 times

scholarly journals A three-site Langmuir adsorption model to elucidate the temperature, pressure, and support dependence of the hydrogen coverage on supported Pt particles

2007 ◽  
Vol 245 (2) ◽  
pp. 415-427 ◽  
Author(s):  
Y JI ◽  
V KOOT ◽  
A VANDEREERDEN ◽  
B WECKHUYSEN ◽  
D KONINGSBERGER ◽  
...  
Keyword(s):  
Adsorption Model ◽  
Langmuir Adsorption ◽  
Langmuir Adsorption Model

scholarly journals Aizoon Extract As a Novel Eco-friendly Corrosion Inhibitor For Stainless Steel430 in HCl Solution

2021 ◽  
Author(s):  
Ahmed F. Molouk ◽  
Mohamed F. Atia ◽  
Abd El-Aziz S. Fouda
Keyword(s):  
Mixed Type ◽  
Electrochemical Impedance ◽  
Theoretical Data ◽  
Cathodic Reaction ◽  
Mass Reduction ◽  
Adsorption Model ◽  
Langmuir Adsorption ◽  
Langmuir Adsorption Model ◽  
Hcl Solution ◽  
Mixed Type Inhibitor

Abstract Aizoon extract used as anti-corrosion for stainless steel430 (SS430) in 2M hydrochloric acid solution. The mass reduction, electrochemical impedance, and potentiodynamic polarization were carried out to demonstrate the performance of Aizoon extract as corrosion resistance for SS430. Polarization revealed that the Aizoon extract is mixed type inhibitor with superiority to inhibiting the cathodic reaction. The inhibition percentage reaches 93% at 300 ppm extract. Adsorption of the extract on SS430 surface is regular with Langmuir adsorption model. Thermodynamic factors for adsorption and activation processes for SS430 dissolution were estimated and discussed. Furthermore, the SS430 surface is characterized using different techniques. The surface morphology of SS430 was tested utilizing several techniques. The experimental data were supported by the theoretical data.

Pumping Effect of Slider Air Bearing Surface for Non-Langmuir Adsorption

2010 ◽  
Author(s):  
Bo Zhang ◽  
Akira Nakajima
Keyword(s):  
Disk Surface ◽  
Air Bearing ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Adsorption Model ◽  
Adsorbed Film ◽  
Disk Interface ◽  
Langmuir Adsorption ◽  
Langmuir Adsorption Model ◽  
Slider Air Bearing

Numerical analysis of the adsorbed film thickness at the air bearing surface is conducted using the non-Langmuir adsorption model. It is found that the adsorbed film at the air bearing surface becomes significant when the viscosity of adsorbed film is higher than about 1 Pa s. The adsorbed contaminant will accumulate at the rear end of the slider, and it is possible that the accumulated liquid-like contaminant may form a liquid tail which will directly contact with the disk surface, resulting in a crush of the head/disk interface.

Measurement of DNA Hybridization by Nano-Deformation of Microcantilever in CMOS Biosensor

2008 ◽  
Author(s):  
S. M. Yang ◽  
T. I. Yin ◽  
C. Chang
Keyword(s):  
Dna Hybridization ◽  
Layer Structure ◽  
Cmos Process ◽  
Insulation Layer ◽  
Adsorption Model ◽  
Nucleotide Polymorphism ◽  
Langmuir Adsorption ◽  
Langmuir Adsorption Model ◽  
Biosensor Chip

A 1 cm × 1 cm biosensor chip for analyzing DNA hybridization is developed by CMOS process. The sensor chip has 6 measurement regions, each region with 3 pairs of parallel microcantilever of 125 × 60 × 0.75μm. The microcantilever is a 4-layer structure composed of an immobilized surface layer, a top insulation layer, an embedded piezoresistive layer, and a bottom insulation layer to measure the nano-deformation induced by the surface-assemble monolayer of alkanethiols on Au. By the Langmuir adsorption model, the estimated adsorption rate of the ssDNA is 0.005sec−1. The design has intrinsic sensitivity needed in biochemical applications such as detecting nucleotide polymorphism and single base mutation to sequence DNA. The capability of in-situ, multipoint measurement promise many frontiers to be explored.

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