Adsorption isotherms and kinetics

Azizian, Saied; Eris, Setareh

doi:10.1016/b978-0-12-818805-7.00011-4

Cited by 73 publications

(45 citation statements)

References 145 publications

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“…Figure 2 shows the adsorption isotherms ( Q ads vs. C eq ) of DF on cAp at 25 °C (a) and 37 °C (c), and on cAp-Tb at 25 °C (e) and 37 °C (g). Adsorption data were fitted to different adsorption models: Langmuir [ 44 , 45 , 46 , 47 , 48 ], Freundlich [ 49 ] and Langmuir-Freundlich [ 30 , 50 , 51 ]. The Langmuir model considers a monolayer of adsorbate and the surface of the adsorbent energetically homogeneous.…”

Section: Resultsmentioning

confidence: 99%

“…The maximum adsorbed amounts Q max , however, are greater at 37 °C, although they do not exceed the 0.063 mg/mg adsorbed on cAp-Tb for an initial DF concentration in the solution of 0.45 mg/mL. The influence of the temperature on the adsorption processes, in general, is well documented [ 51 ]. Adsorption is an exothermic phenomenon, and thus an increase in temperature leads to a decrease in the adsorption capacity, which results in a lower K LF , but, at the same time, it favours the solvate-solvate interaction so that the outermost layers attract a greater number of molecules.…”

Section: Discussionmentioning

confidence: 99%

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Biomimetic Citrate-Coated Luminescent Apatite Nanoplatforms for Diclofenac Delivery in Inflammatory Environments

et al. 2022

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Luminescent nanoparticles are innovative tools for medicine, allowing the imaging of cells and tissues, and, at the same time, carrying and releasing different types of molecules. We explored and compared the loading/release ability of diclofenac (COX-2 antagonist), in both undoped- and luminescent Terbium3+ (Tb3+)-doped citrate-coated carbonated apatite nanoparticles at different temperatures (25, 37, 40 °C) and pHs (7.4, 5.2). The cytocompatibility was evaluated on two osteosarcoma cell lines and primary human osteoblasts. Biological effects of diclofenac-loaded-nanoparticles were monitored in an in vitro osteoblast’s cytokine–induced inflammation model by evaluating COX-2 mRNA expression and production of PGE2. Adsorption isotherms fitted the multilayer Langmuir-Freundlich model. The maximum adsorbed amounts at 37 °C were higher than at 25 °C, and particularly when using the Tb3+ -doped particles. Diclofenac-release efficiencies were higher at pH 5.2, a condition simulating a local inflammation. The luminescence properties of diclofenac-loaded Tb3+ -doped particles were affected by pH, being the relative luminescence intensity higher at pH 5.2 and the luminescence lifetime higher at pH 7.4, but not influenced either by the temperature or by the diclofenac-loaded amount. Both undoped and Tb3+-doped nanoparticles were cytocompatible. In addition, diclofenac release increased COX-2 expression and decreased PGE2 production in an in vitro inflammation model. These findings evidence the potential of these nanoparticles for osteo-localized delivery of anti-inflammatory drugs and the possibility to localize the inflammation, characterized by a decrease in pH, by changes in luminescence.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Biomimetic Citrate-Coated Luminescent Apatite Nanoplatforms for Diclofenac Delivery in Inflammatory Environments

et al. 2022

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“…The Langmuir isotherm suggests that monolayer adsorption of metal ions happens on the same active sites on the surface of the adsorbent. This is due to the fact that the sites are uniform and have the same energy levels [42]. The Freundlich isotherm suggests that the adsorbent's surface is heterogeneous, which supports the fact that adsorption occurs on a surface made up of heterogeneous patches [43].…”

Section: Langmuir and Freundlich Isothermsmentioning

confidence: 60%

Adsorption Behavior of Heavy Metal Ions by Hybrid Inulin-TEOS for Water Treatment

et al. 2022

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The present work reports the adsorption behavior involved in the adsorption of heavy metal ions using a hybrid inulin-tetraethoxysilane (TEOS) adsorbent produced through the sol-gel process. An aqueous multi-element solution was used in order to examine the inulin-TEOS adsorbent efficiency in removing Cd2+, Co2+, and Ni2+ ions. The effects of the contact duration, adsorbent dosage, initial concentration, and solution pH on the adsorption of the targeted metal ions in batch systems were evaluated. The optimal conditions for the removal of all targeted heavy metals were as follows: 30 mg of an adsorbent dosage at pH 4 and 5 minutes of contact time with an initial concentration of 0.5 mg/L. A one-way analysis of variance (one-way ANOVA) with a replication test showed that all parameters had significant differences at a p-value of 0.05. At the optimum condition, 92.59%, 90.27%, and 86.472% of Cd2+, Ni2+, and Co2+ were removed, respectively. Findings from kinetic studies suggest that the pseudo-second order model can successfully describe the overall adsorption process. Additionally, the adsorption process can be adequately explained using an intra-particle diffusion model with diffusion rate constants following the sequence of Kint,1 > Kint,2 for Co2+ and Ni2+ and Kint,1 > Kint,2 > Kint,3 for Cd2+ in each step. The results suggest that Ni2+ fits with the Langmuir isotherm, while Cd2+ and Co2+ better fit the Freundlich one. Finally, the adsorbent can be reused and is able to retain a good percentage of removal, with percentage difference decreases of 1.99%, 3.29%, and 4.12% for Cd2+, Ni2+, and Co2+, respectively, after the fifth cycle. The hybrid inulin-TEOS bio-sorbent has good adsorption capacity and durability, which could offer a low-cost practical cleaner production process for removing targeted analytes from wastewater. Doi: 10.28991/CEJ-2022-08-09-03 Full Text: PDF

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“…The majority of tracers are salts or substances with a low reactivity. Since then, the migration and transformation of heavy metals in the unsaturated zone has been gradually studied, the distribution coefficients of soil liquid and solid concentrations are considered, and the liquid phase is represented by the Henry, Freundlich, and Langmuir isotherm adsorption model (25). Currently, the relationship between the adsorption and desorption of solid phase concentration and the non-equilibrium adsorption and desorption problem is being investigated.…”

Section: Status Quo Of the Migration And Transformation Of Contaminan...mentioning

confidence: 99%

A Narrative Review of Groundwater and Soil Pollution

Luz¹

2022

Sci Insights

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In accordance with the migration and transformation laws of pollutants in soil and groundwater, the research progress of chemical fertilizers, pesticides, and sewage irrigation is reviewed systematically from three perspectives: the topsoil layer, the underground aquifer, and the unsaturated zone. The results of the study of migration and transformation in various water layers and unsaturated soils illuminate the current research's problems and future directions.

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Adsorption isotherms and kinetics

Cited by 73 publications

References 145 publications

Biomimetic Citrate-Coated Luminescent Apatite Nanoplatforms for Diclofenac Delivery in Inflammatory Environments

Biomimetic Citrate-Coated Luminescent Apatite Nanoplatforms for Diclofenac Delivery in Inflammatory Environments

Adsorption Behavior of Heavy Metal Ions by Hybrid Inulin-TEOS for Water Treatment

A Narrative Review of Groundwater and Soil Pollution

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