scholarly journals Freundlich Isotherm: An Adsorption Model Complete Framework

2021 ◽  
Vol 11 (17) ◽  
pp. 8078
Author(s):  
Michael Vigdorowitsch ◽  
Alexander Pchelintsev ◽  
Liudmila Tsygankova ◽  
Elena Tanygina

The absolute majority of modern studies dealing with the interpretation of experimental data on the basis of the Freundlich isotherm ignore the fact that the data obtained for regions of low and moderate adsorbate concentration/pressure can be analytically continued within the Freundlich adsorption model to the adsorptive saturation area with coverages tending to 100%. Needless to say, this would give valuable extended information about the corresponding adsorption process. This message proposes a framework to comprehensively analyse experimental data first recognised as complying with the Freundlich adsorption model. An algorithm-driven method is presented which enables one to translate the data obtained in the area of small and moderate the coverages of the area of adsorptive saturation regime. As examples, three sets of experimental data for adsorption of mercury (II) on N-rich porous organic polymers and of protein on carrier nano-Mg(OH)2 have been processed and presented according to the framework developed.

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1251
Author(s):  
Michael Vigdorowitsch ◽  
Alexander N. Pchelintsev ◽  
Liudmila E. Tsygankova

Using experimental data for the adsorption of phosphates out of wastewater on waste recycled bricks, published independently in MDPI Processes before (2020), this message re-visits the mathematical theory of the Freundlich adsorption model. It demonstrates how experimental data are to be deeper treated to model the saturation regime and to bridge a chasm between those areas where the data fit the Freundlich power function and where a saturation of surface adsorption centers occurs.


Konversi ◽  
2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Nadya Hasna ◽  
Dedy Suprayogi ◽  
Abdul Hakim

Ketapang contains tannin and phenolic compounds which are known to absorb metals and pollutants in the air. The purpose of this study was to determine the effectiveness of the biadsorbent from ketapang leaves (Terminalia sp.) on the adsorption of Rhodamine B dye without activation and with activation by 10% phosphoric acid. The study began with testing the variation of mass, time, and concentration of Rhodamine B by ketapang leaves. Then the adsorption process was carried out using a batch system and the concentration of the filtrate was measured using a UV-Vis spectrophotometer. Followed by the isotherm analysis of Freundlich and Langmuir. The results showed that the bioadsorbent ability of ketapang leaves without activation or with activation by 10% H3PO4 in terms of mass variation, contact time, and Rhodamine B concentration were 300 mg, contact time was 90 & 120 minutes, and Rhodamine B concentration was 10 mg/l. - 30 mg/l. The maximum bioadsorbent capacity of ketapang leaves (Qm) without activation was 3.7037 mg/g, while that of ketapang leaves with phosphoric acid activation was 1.0673 mg/g. The adsorption model used by the ketapang leaf bioadsorbent is the Freundlich isotherm where the R2 value close to 1 is 0.9573.


2020 ◽  
Vol 1002 ◽  
pp. 489-497
Author(s):  
Zainab Hussain ◽  
Zeyad Fadhil ◽  
Sameer Kareem ◽  
Salam Mohammed ◽  
Emad Yousif

In the present study, removal of safranin dye from water bodies was investigated using natural biosorbent (Thyme leaves (TEL)). The influence of multiple factors such as as contact time (15 – 105 mins), adsorbent dose (25 to 350) mg/l , adsorbate dose (5 to 40)mg\L, and temperature (25 to 55)o C were taken for investigation. The adsorption isotherms were described by utilized Langmuir, Freundlich and Dubnin-Radushkevich models, Freundlich isotherm model found to be best suited with experimental data out of 3 isotherm The adsorption process followed pseudo second order model.


Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 203
Author(s):  
Wenjie Nie ◽  
Jiao Liu ◽  
Xue Bai ◽  
Zefeng Xing ◽  
Ying Gao

Adsorption is an effective method to remove tetracycline (TC) from water, and developing efficient and environment-friendly adsorbents is an interesting topic. Herein, a series of novel phenyl porous organic polymers (P-POPs), synthesized by one-pot polymerization of different ratios of biphenyl and triphenylbenzene under AlCl3 catalysis in CH2Cl2, was studied as a highly efficient adsorbent to removal of TC in water. Notably, the obtained POPs possessed abundant phenyl-containing functional groups, large specific surface area (1098 m2/g) with abundant microporous structure, high pore volume (0.579 cm3/g), favoring the removal of TC molecules. The maximum adsorption capacity (fitted by the Sips model) could achieve 581 mg/g, and the adsorption equilibrium is completed quickly within 1 h while obtaining excellent removal efficiency (98%). The TC adsorption process obeyed pseudo-second-order kinetics and fitted the Sips adsorption model well. Moreover, the adsorption of POPs to TC exhibited a wide range of pH (2–10) adaptability and outstanding reusability, which could be reused at least 5 times without significant changes in structure and efficiency. These results lay a theoretical foundation for the application of porous organic polymer adsorbents in antibiotic wastewater treatment.


Author(s):  
Pramod Kumar ◽  
Animesh Das ◽  
Biplab Maji

The phosphorous-containing porous organic polymer is a trending material for the synthesis of heterogeneous catalysts. Decades of investigations have established phosphines as versatile ligands in homogeneous catalysis. Recently, phosphine-based heterogeneous...


2021 ◽  
Author(s):  
Yanpei Song ◽  
Pui Ching Lan ◽  
Kyle Martin ◽  
Shengqian Ma

Conjugated microporous polymers (CMPs) are an emerging class of porous organic polymers that combine -conjugated skeletons with permanent micropores. Since their first report in 2007, the enormous exploration of linkage...


Author(s):  
Tianhao Zhu ◽  
Benbing Shi ◽  
Hong Wu ◽  
Xinda You ◽  
Xiaoyao Wang ◽  
...  

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