adsorption models
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2022 ◽  
pp. 63-99
Author(s):  
Giovanni Palmisano ◽  
Samar Al Jitan ◽  
Corrado Garlisi

2021 ◽  
Author(s):  
Reda Marouf ◽  
Nacer Dali ◽  
Nadia Boudouara ◽  
Fatima Ouadjenia ◽  
Faiza Zahaf

The clay used in this study was the bentonite from Mostagnem, Algeria. This material is used in many fields such as drilling, foundry, painting, ceramics, etc. It can also be applied in the treatment of wastewaters from chemical industries by means of adsorption. In this chapter the physicochemical properties of bentonite were determined by using several analyses techniques such as chemical composition, XRD, FTIR and SBET. The bentonite was intercalated by aluminum poly-cations solution and cethytrimethyl ammonium bromide. The acid activation of natural bentonite was performed by treatment with hydrochloric acid at different concentrations. The surface water pollutants removed by the modified bentonites are bemacid yellow E-4G and reactive MX-4R dyes, and fungicide chlorothalinil. The Langmuir and Freundlich adsorption models were applied to describe the related isotherms. The pseudo-first order and pseudo-second order kinetic models were used to describe the kinetic data. The changes of enthalpy, entropy and Gibbs free energy of adsorption process were also calculated.


Author(s):  
Asep Bayu Dani Nandiyanto ◽  
◽  
Nissa Nur Azizah ◽  
Salma Rahmadianti ◽  
◽  
...  

The purpose of this study was to make carbon from banana stem waste and determine the isotherm adsorption characteristics of carbon from banana stem waste to methyl orange compounds. The process for making carbon from banana stem waste was done through the stages of preparation and carbonization at a temperature of 250°C for 1.5 h. Before being used as carbon, banana stem waste was cleaned, washed, dried, and mashed using a mill. The carbon then went through a washing process to remove impurities and tested for its absorbance ability into a solution containing a methyl orange compound under constant conditions of pH, temperature, and pressure. The experimental results showed that the appropriate sequence of adsorption models is the Langmuir, Temkin, Freundlich, and Dubinin-Radushkevich models. Adsorption occurs on the surface of a single layer (monolayer) and the interaction between the adsorbent and the adsorbate occurs physically. The value of maximum adsorption capacity (Qmax) is 37.5940 mg/g. The presence of banana stem carbon is expected to reduce the negative impacts, one of which is the disposal of industrial wastewater from textile factories.


2021 ◽  
Vol 12 (6) ◽  
pp. 8042-8056

In recent years, the presence of pharmaceutical contaminants, such as diclofenac sodium (DCF) in water bodies and their potential influence on aquatic organisms gained much attention. As a result of high demand and usage by consumers, in addition to incomplete removal during wastewater treatment, pharmaceutical contaminants will end up on water surfaces. To mitigate this problem, the elimination of DCF by employing activated carbon derived from Dillenia Indica peels was evaluated. The adsorption of DCF was performed in a continuous process. The findings showed that the adsorption of DCF was favorable at a lower flow rate, greater bed height, and initial DCF concentration, with the highest removal percentage of 44.93%. To assess the characteristics of the breakthrough curve of DCF, the adsorption data were used to match three distinct adsorption models, namely, Boharts and Adam, Yoon-Nelson, and Thomas. The breakthrough results were well-fitted with these models, as the values of R2 for all models and parameters were higher than 0.88. Thus, it was concluded that the activated carbon from Dillenia Indica can effectively remove DCF from an aqueous solution.


2021 ◽  
Author(s):  
BENSEDIRA Abderrahim ◽  
HADDAOUI Nacerddine ◽  
DOUFNOUNE Rachida ◽  
MEZIANE Ouahiba ◽  
N. S. Labidi

Abstract Conducting Polymeric composites have attracted great attention over the last years because of their potential uses in chemical, electronic and optical devices, and as catalysts as well as in adsorption processes. Chemical synthesis of polyaniline (PANI) and polyaniline-SiO2 composite and their adsorptive performance were reported in the present work. These materials were prepared and evaluated for their methylene blue (MB) dye adsorption characteristics from aqueous solution. Adsorption equilibrium kinetic and thermodynamic experiments of MB onto PANI and PANI/SiO2 were studied. The effects of initial dye concentration, contact time and temperature on the adsorption capacity of PANI/SiO2 for MB have been investigated. The pseudo-first order and pseudo-second order kinetic models were used to describe the kinetic data. It was found that adsorption kinetics followed the pseudo-second order at all of the studied temperatures. The Langmuir, Freundlich and Dubinin Raduschkevich adsorption models were used for the mathematical description and the fit obtained using the Dubinin Raduschkevich isotherm has a medium R2 value.


2021 ◽  
Vol 40 (3) ◽  
pp. 28-42
Author(s):  
Y. Walid AlBizreh ◽  
rasha Almostafa ◽  
Malak ALJoubbeh

The boiled tea leaves residual was modified with oleum of weight 1:1 to prepare an adsorbent that is capable to adsorb nicotine on its surface. The surface properties of the sample were studied by using the FT-IR spectroscopy after each treatment resulting obvious peaks that indicate the modification of the sample with oleum and the adsorption of nicotine on its surface. The concentration of nicotine in the prepared solutions was measured by the use of spectral analysis. The change of nicotine΄s adsorption was studied with the change of time. An increase in the adsorbed amount was noticed until the equilibrium was reached after 24hours. In addition, an increase of the adsorbed amount of nicotine with the increase of its initial concentration was observed at the room temperature. The experimental data corresponded with adsorption models of Langmuir, Freundlish and Temkin, besides, a mechanism of the adsorption of nicotine was suggested to occur with the participation of the two nitrogen atoms.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5824
Author(s):  
Wenxin Li ◽  
Jiawen Wang ◽  
Wanyu Ding ◽  
Youping Gong ◽  
Huipeng Chen ◽  
...  

Metal atoms were deposited on an Si (111)-7 × 7 surface, and they were adsorbed with alcohol gases (CH3OH/C2H5OH/C3H7OH). Initially, CnH2n+1OH adsorption was simply used as an intermediate layer to prevent the chemical reaction between metal and Si atoms. Through scanning tunneling microscopy (STM) and a mass spectrometer, the CnH2n+1OH dissociation process is further derived as the construction of a surface quasi-potential with horizontal and vertical directions. With the help of three typical metal depositions, the surface characteristics of CH3OH adsorption are more clearly presented in this paper. Adjusting the preheating temperature, the difference of thermal stability between CH3O– and H+ could be obviously derived in Au deposition. After a large amount of H+ was separated, the isolation characteristic of CH3O– was discussed in the case of Fe deposition. In the process of building a new metal-CH3O–-H+ model, the dual characteristics of CH3OH were synthetically verified in Sn deposition. CH3O– adsorption is prone to influencing the interaction between the metal deposition and substrate surface in the vertical direction, while H+ adsorption determines the horizontal behavior of metal atoms. These investigations lead one to believe that, to a certain extent, the formation of regular metal atomic structures on the Si (111)-7 × 7-CH3OH surface is promoted, especially according to the dual characteristics and adsorption models we explored.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hongchuan Li ◽  
Rui Jin ◽  
Hongxiang Hu ◽  
Yusef Kianpoor Kalkhajeh ◽  
Yingying Zhao ◽  
...  

Sodium alginate (SA), polyvinyl oxide (PEO), and ceramic nanomaterials were used to prepare alginate composite gel. The present study examined the removal rate and adsorption capacity of alginate composite gel for removal of wastewater As(III), Pb(II), and Zn(II). Batch experiments were conducted to study the influence of experimental parameters such as pH and temperature, as well as the mechanism of As(III), Pb(II), and Zn(II) adsorption with the new adsorbent. The results showed the high efficiency of sodium alginate composite gel for removal of wastewater As(III), Pb(II), and Zn(II). Under the condition of the best liquid-solid ratio and the contact time, the removal rates of As(III), Pb(II), and Zn(II) were 67.42%, 95.31%, and 93.96%, respectively. The pseudo-second-order kinetic equation was superior to fit the adsorption kinetics process. The isothermal adsorption models of As(III) and Pb(II) fitted well with the Freundlich model, and Zn(II) fitted well with the Langmuir model. The results of SEM, EDS, XPS, and FTIR analyses revealed that the adsorption process occurred mainly via chemisorption. The results of the present study suggest that new adsorbents can be effectively utilized for As(III), Pb(II), and Zn(II) removal from water.


2021 ◽  
Vol 2 (2) ◽  
pp. 19-32
Author(s):  
Hawraa Kassem Hami ◽  
Ruba Fahmi Abbas ◽  
Emad Mahmoud Eltayef ◽  
Neda Ibrahim Mahdi

Metal oxides are widely used in adsorption technology as adsorbent surfaces because of their efficiency, low cost and unique physical properties. The aim of this review to clarify the role of aluminium oxide and Nano aluminium oxide in removing some chemicals contain that influence on human health such as dyes, antibiotics, and heavy metals. This paper also includes the affective of some adsorption parameters like pH, contact time, removal percentageand temperature. The Adsorption nature, kinetic adsorption models and isotherm models are also reported here.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1473
Author(s):  
Ahmed Raslan ◽  
Jesús Ciriza ◽  
Ana María Ochoa de Retana ◽  
María Luisa Sanjuán ◽  
Muhammet S. Toprak ◽  
...  

Modifying hydrogels in order to enhance their conductivity is an exciting field with applications in cardio and neuro-regenerative medicine. Therefore, we have designed hybrid alginate hydrogels containing uncoated and protein-coated reduced graphene oxide (rGO). We specifically studied the adsorption of three different proteins, BSA, elastin, and collagen, and the outcomes when these protein-coated rGO nanocomposites are embedded within the hydrogels. Our results demonstrate that BSA, elastin, and collagen are adsorbed onto the rGO surface, through a non-spontaneous phenomenon that fits Langmuir and pseudo-second-order adsorption models. Protein-coated rGOs are able to preclude further adsorption of erythropoietin, but not insulin. Collagen showed better adsorption capacity than BSA and elastin due to its hydrophobic nature, although requiring more energy. Moreover, collagen-coated rGO hybrid alginate hydrogels showed an enhancement in conductivity, showing that it could be a promising conductive scaffold for regenerative medicine.


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