Experimental relation between Dubinin-Radushkevich equation and Langmuir equation for various adsorbates on many carbons

Carbon ◽  
1993 ◽  
Vol 31 (6) ◽  
pp. 990-992 ◽  
Author(s):  
M. Kobayashi ◽  
E. Ishikawa ◽  
Y. Toda
Keyword(s):  
Langmuir Equation ◽  
Experimental Relation

Applicability of the Langmuir equation to simulate the vertical mass flux profile

2021 ◽  
Vol 14 (16) ◽  
Author(s):  
Huanyu Shi ◽  
Zhibao Dong ◽  
Nan Xiao ◽  
Qinni Huang
Keyword(s):  
Mass Flux ◽  
Langmuir Equation ◽  
Flux Profile

scholarly journals The adsorption of vapours on mercury. I. Non-polar substances

1946 ◽  
Vol 187 (1008) ◽  
pp. 53-73 ◽  
Keyword(s):  
Free Energy ◽  
Total Energy ◽  
Langmuir Equation ◽  
Phase Changes ◽  
Two Dimensional ◽  
Surface Phase ◽  
Standard State ◽  
Spreading Pressure ◽  
Benzene Toluene ◽  
Entropy Of Adsorption

Reversible results for the adsorption of benzene, toluene and n -heptane vapours on mercury have been obtained. The films were found to be gaseous and obeyed the Volmer eqution F ( A - b ) = kT , where F = spreading pressure, A =area per molecule and b = co-area. The possibility that the films might be immobile was considered and the Langmuir equation was applied but found unsatisfactory. A standard state for the surface phase was defined and the free energy, total energy and entropy of adsorption evaluated. The heat of adsorption was shown to increase with the amount on the surface. A number of phase changes were found to occur after the completion of monolayer adsorp­tion, the most striking being interpreted as the change over from ‘flat’ to ‘vertical’ adsorp­tion of the toluene molecules. Others were thought to be either two-dimensional condensation or adsorption of a second layer.

Comparative study of isotherm parameters of lead biosorption by two wastes of olive-oil production

2015 ◽  
Vol 72 (5) ◽  
pp. 711-720 ◽  
Author(s):  
G. Blázquez ◽  
A. Ronda ◽  
M. A. Martín-Lara ◽  
A. Pérez ◽  
M. Calero
Keyword(s):  
Experimental Data ◽  
Olive Tree ◽  
Langmuir Equation ◽  
Equilibrium Isotherm ◽  
Chemical Treatments ◽  
Olive Stone ◽  
Loss Of Mass ◽  
Best Fit ◽  
Tree Pruning ◽  
Effectiveness Coefficient

Batch isotherm studies were carried out on a laboratory scale: (i) to investigate the effectiveness to remove lead of two wastes (olive stone (OS) and olive tree pruning (OTP)), untreated and chemically treated; and (ii) to examine the applicability of various adsorption isotherms to fit the experimental data. Results from tests were analyzed using seven equilibrium isotherm correlations (Langmuir, Freundlich, Dubinin–Radushkevich, Temkin, Redlich–Peterson, Sips, and Toth equations). The sum of the squares of the errors was determined for each isotherm and the Langmuir equation provided the best fit. Chemical treatments increased the biosorption properties of these materials. The maximum biosorption capacities were: 6.33, 49.13, 14.83, and 38.93 mg g−1 for untreated OS, HNO3-OS, H2SO4-OS, and NaOH-OS, respectively, and 26.72, 86.40, 72.78, and 123.80 mg g−1 for untreated OTP, HNO3-OTP, H2SO4-OTP, and NaOH-OTP, respectively. Finally, the loss of mass for each waste (13.9, 14.3, and 36.8% for HNO3-OS, H2SO4-OS, and NaOH-OS and 35.1, 27.5, and 46.7% for HNO3-OTP, H2SO4-OTP, and NaOH-OTP, respectively) was taken into account and an effectiveness coefficient was determined for each adsorbent material.

scholarly journals STUDI KINETIKA ADSORPSI Pb MENGGUNAKAN ARANG AKTIF DARI KULIT PISANG

Konversi ◽  
2015 ◽  
Vol 4 (1) ◽  
pp. 17
Author(s):  
Ari Susandy Sanjaya ◽  
Rizcy Paramita Agustine
Keyword(s):  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Langmuir Equation ◽  
Kinetics Model ◽  
Banana Peel ◽  
Maximum Adsorption Capacity ◽  
Kinetics Analysis ◽  
Optimum Time ◽  
Lead Metal ◽  
Isotherm Equations

Abstrak- Logam Pb merupakan salah satu pencemar lingkungan dan dapat mengakibatkan kematian atau gangguan kesehatan dalam waktu singkat. Salah satu cara untuk mengatasi masalah pencemaran Pb adalah dengan menggunakan arang aktif dari kulit pisang. Penelitian ini bertujuan untuk menentukan model kinetika yang sesuai pada proses adsorpsi Pb dengan melihat daya jerap arang aktif kulit pisang dalam berbagai variasi massa (1 g; 1,5g dan 2 g) dan waktu kontak (20 menit, 40 menit dan 60 menit). Analisa Kinetika didasarkan pada kinetika orde nol, orde satu dan orde dua serta menentukan kapasitas maksimum adsorpsi arang atif kulit pisang  terhadap logam Pb. Persamaan yang digunakan dalam proses adsorpsi adalah persamaan adsorpsi Isoterm Langmuir dan Freundlich. Dari hasil analisa, waktu optimum adsorbsi terjadi pada waktu 60 menit.  Kinetika adsorbsi logam Pb dengan arang aktif dari kulit pisang pada massa 1 dan 2 g mengikuti model kinetika orde 2, sedangkan pada massa 1,5 g mengikuti kinetika orde 0. Persamaan adsorpsi Langmuir lebih sesuai untuk isotherm adsorpsi pada penelitian ini. Adsorpsi Pb oleh kulit pisang yang sesuai dengan pola isotherm adsorpsi Langmuir mengindikasikan bahwa adsorpsi hanya berlangsung satu lapis (monolayer). Kapasitas adsorpsi maksimum ditunjukkan oleh nilai a yang besar, yaitu 1,4582 pada massa 1 g sedangkan kekuatan interaksi antara ion Pb2+ dengan kulit pisang terjadi pada massa 2 g yang ditunjukkan dengan nilai kL yang besarnya 0,409 Kata kunci : kinetika adsorpsi, arang aktif, kulit pisang, logam Pb  Abstract- Lead metal is one of environment polluter and can cause decease or health problems in sort time. The way to solve this problem is with used the carbon active from banana peel. This research is intend to find the kinetics model that appropriate in Pb adsorption process by knowing absorption of banana peel carbon active within mass variations (1; 1,5 and 2 g) and contact time (20, 40, and 60 minutes). Kinetics analysis are based from orde zero,one, and two and find the maximum capacity of adsorption from banana peel carbon active to lead metal. Equation which using at the adsorption process are Langmuir and Freundlich isotherm equations. From the analysis results, optimum time is at 60 minutes.kinetics of Pb absorption with carbon active from banana peel in mass 1 and 2 gr following kinetics model orde 2, then in mass 1,5 g following kinetics model orde 0. Langmuir equation is more appropriate in this research. Pb absorption from the banana peel that appropriate to Langmuir isotherm system is indicates adsorption was occur in one layer (monolayer). Maximum adsorption capacity is showing by the bigger value from a, that is 1,4582 in mass 1 g then interaction power of Pb with the banana peel was occur in mass 2 gr which showing with the value of kL is 0,4090.  Keywords : adsorption kinetics, carbon active, banana peel, Pb metal

THE SORPTION OF ACIDS BY WOOL

1949 ◽  
Vol 27b (12) ◽  
pp. 879-889 ◽  
Author(s):  
R. Donovan ◽  
P. Larose
Keyword(s):  
Hydrochloric Acid ◽  
Adsorption Isotherm ◽  
Sulphuric Acid ◽  
Sodium Sulphate ◽  
Langmuir Adsorption Isotherm ◽  
Langmuir Equation ◽  
Recent Application ◽  
Satisfactory Explanation ◽  
Isotherm Equation ◽  
Langmuir Adsorption

The amount of acid sorbed by wool from solutions of sulphuric acid of four different strengths (namely, 0.0505, 0.0339, 0.0182, and 0.0101 molar) and containing sodium sulphate in amounts varying up to 0.16 molar has been determined. It has been found that the presence of the salt has little effect on the quantity of acid sorbed within those limits. The results are analyzed in the light of the theory of Gilbert and Rideal but this theory fails to give a satisfactory explanation of the results obtained. It is possible, however, to explain the results of the authors' experiments on the basis of the recent application of the Donnan equilibrium by Peters and Speakman. The Langmuir adsorption isotherm equation has been applied to data on the absorption of hydrochloric acid and of sulphuric acid by wool. The data appear to fit the Langmuir equation and give, for the maximum combining capacity, values that agree well with those estimated in other ways.

scholarly journals The binary gas sorption in the bituminous coal of the Huaibei Coalfield in China

2018 ◽  
Vol 36 (9-10) ◽  
pp. 1612-1628 ◽  
Author(s):  
Lei Zhang ◽  
Zhiwei Ye ◽  
Mingxue Li ◽  
Cun Zhang ◽  
Qingsheng Bai ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Sorption Capacity ◽  
Bituminous Coal ◽  
Gas Adsorption ◽  
Langmuir Equation ◽  
Separation Coefficient ◽  
Gas Sorption ◽  
Langmuir Adsorption ◽  
Gas Molecules ◽  
Huaibei Coalfield

Knowledge of the gas sorption characteristics of a coal not only helps to explain the mechanism of enhanced coalbed methane recovery but also provides an important basis for simultaneous coal and gas extraction. In consequence, the pure and binary gas excess sorption capacity of methane, carbon dioxide, and nitrogen of bituminous coal samples derived from the Xutuan Coal Mine in Huaibei coalfield, in Anhui Province in China, was measured using the volumetric method. The fitting analysis of the pure gas Langmuir adsorption model was carried out. The binary gas excess sorption measurement showed that the final sorption capacity of bituminous samples was the same no matter what the gas adsorption order of competitive adsorption and displacement adsorption. Hence, coal gas adsorption is physical adsorption, i.e. the different adsorption and desorption process of gas molecules does not affect the final adsorption amount of coal to each component of gas. Using the fitting parameters obtained by the Langmuir equation, the extended Langmuir equation was used to predict the adsorption capacity for each component of the binary gas. The comparison between predicted adsorption capacity and measured adsorption capacity showed that the extended Langmuir equation can better describe the trend of the adsorption isotherm curves of a binary gas under different pressures. The separation coefficient and displacement coefficient were defined from Langmuir adsorption theory. The separation coefficient involves the proportion of each component in the free phase and the proportion of each component in the adsorption phase. The displacement coefficient involves the displacement ability of gas molecules at adsorption sites by free gas molecules.

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