Surface area of activated charcoal by Langmuir adsorption isotherm

1961 ◽  
Vol 38 (7) ◽  
pp. 357 ◽  
Author(s):  
Boleslaw Ludwik Dunicz
Jurnal Kimia ◽  
2016 ◽  
Author(s):  
I Made Dupi Andika ◽  
I Nengah Simpen ◽  
Ketut Gede Dharma Putra

This research discusses the adsorption-desorption of Cr(VI) by the adsorbent made from Karangasem cadas rock which is the waste of Balinese temple production. The adsorbent was activated with  NaOH and coated with Fe(OH)3. The aim of the study was to investigate the capability of cadas rock in Cr6+ adsorption. The rock was activated with various concentrations of NaOH followed by coating process with Fe(OH)3. Each adsorbent was characterized for its specific surface area and surface acidity. The equilibrium time, adsorption isotherms and adsorption capacity were also investigated. The adsorbent with the highest adsorption capacity was then desorbed using HNO3 2 mol/L, NaOH 1 mol/L, and saturated NH4Cl. The result suggested that the highest surface acidity was showed by the control adsorbent which was 0.2836 ± 0.0106 mmol/g with an acid site of 1.7079 x 1020 atoms/g. The highest spesific surface area was showed by the adsorbent activated with 6M NaOH  and coated with Fe(OH)3, which was 34.5042 m2/g. The highest adsorption capacity was showed by the same adsorbent, which was 2.5253 mg/g with interaction time of 15 minutes at pH 5. This met the pattern of Langmuir adsorption isotherm. HNO3 was the most effective desorption substance resulted in a percentage of Cr desorbed of 2,15%.


2010 ◽  
Vol 10 (3) ◽  
pp. 320-326 ◽  
Author(s):  
Sunardi Sunardi ◽  
Yateman Yateman Arryanto ◽  
Sutarno Sutarno

Preparation, activation and adsorption study of natural kaolin from Tatakan, Tapin, South Kalimantan have been conducted. The activation of kaolin was done using 6 M HCl solutions at 90 °C for 3 h. The characterizations of kaolin were carried out by Fourier Transform Infrared, X-ray diffraction, and surface area analyzer. Adsorption parameters studied included the effect of pH, contact time, and concentration of gibberellic acid (GA3) onto kaolin samples. The amount of gibberellic acid adsorbed was determined using UV spectrophotometer. The adsorption capacity of kaolin was determined by Langmuir adsorption isotherm model. The result showed that activation of kaolin was resulted the larger specific surface area and more homogeneous composition of kaolin without any destruction of kaolin structure. Adsorption of gibberellic acid onto kaolin before and after activation showed that optimal adsorption was obtained at pH » 7 and reached the equilibrium within 4 h. The calculations result by Langmuir adsorption isotherm model showed that the increasing of adsorption capacity of acid activated kaolin is about 35%.


1981 ◽  
Vol 77 (4) ◽  
pp. 475-487 ◽  
Author(s):  
S McLaughlin ◽  
J Brown

The Fick diffusion equation is combined with the Langmuir adsorption isotherm and the relevant equations from the Gouy-Chapman theory of the electrical diffuse double layer to demonstrate that the effective diffusion coefficient of calcium ions, both in the cytoplasm of the rod outer segment and within the aqueous space bounded by the disk membrane, should be reduced by a factor of 10-100 because these ions adsorb to phospholipids present in the disk membrane.


1965 ◽  
Vol s3-106 (76) ◽  
pp. 299-306
Author(s):  
D. J. GOLDSTEIN

If two histological sections, of thickness nµ and 2nµ, and having the same apparent intensity of staining, are at equilibrium with dyebaths of concentration B1 and B2 respectively, the affinity of the histological substrate for the dye is, under denned conditions, given by the expression ΔF° = - RT In I/B, where B is either (i) B2 if the thinner section is stained to saturation, or (ii) B1 if B1 = 3B2. The affinity tends to be greater when measured in a weaker dyebath, as implied in method (ii). Evidence is presented suggesting that the uptake of the basic dye Azure A by pancreatic basal chromidial substance, goblet cell mucin and intestinal epithelial cytoplasm follows a Langmuir adsorption isotherm to a first approximation, in that, at low dyebath concentrations, the uptake of dye is proportional to the concentration of dyebath with which the substrate is in equilibrium, while in strong dyebaths the uptake approaches a plateau. A deviation from the ideal Langmuir isotherm in dyebaths of moderate concentration, observed in epithelial cytoplasm and to a lesser extent in pancreatic basal chromidial substance, may have been due to interaction between neighbouring dye-binding sites, or to the presence in a single area of sites with different affinities for the dye.


1949 ◽  
Vol 27b (12) ◽  
pp. 879-889 ◽  
Author(s):  
R. Donovan ◽  
P. Larose

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.


2014 ◽  
Vol 511-512 ◽  
pp. 55-58
Author(s):  
Zhe Qin ◽  
Qian Wang ◽  
Zheng Liu

This paper regarded the sediments of Lake Baiyangdian as the object of study, researched and analyzed ammonia nitrogen adsorption characteristics of sediment samples. The results showed that: the sediments adsorption to ammonia nitrogen reached a state of equilibrium after 2.5h, The ammonia nitrogen adsorption rate was maximum in 0~10min. Sediment adsorption of ammonia nitrogen was higher as ammonia nitrogen liquid balance concentration increased. The adsorption isotherm curve of ammonia nitreogen can be fitted well by the Langmuir adsorption isotherm model. The total maximum adsorption quantity of ammonia nitrogen by the sediments of Lake Baiyangdian is between 54.12mg/kg to 240.12mg/kg.


2015 ◽  
Vol 39 (5) ◽  
pp. 3835-3844 ◽  
Author(s):  
Sachin Mane ◽  
Surendra Ponrathnam ◽  
Nayaku Chavan

Langmuir adsorption isotherm demonstrates monolayer drug loading with hyperhydrophilic three-dimensional crosslinked polymers. Furthermore, the pseudo order kinetics were also evaluated.


Sign in / Sign up

Export Citation Format

Share Document