scholarly journals Approximate description of multi-solute adsorption equilibrium in organic aqueous solution.

1981 ◽  
Vol 14 (1) ◽  
pp. 26-31 ◽  
Author(s):  
MORIO OKAZAKI ◽  
HIROYUKI KAGE ◽  
FUMIO IIJIMA ◽  
RYOZO TOEI
1981 ◽  
Vol 14 (1) ◽  
pp. 73-75 ◽  
Author(s):  
HIROYUKI KAGE ◽  
IKUYA HASHIZUME ◽  
MORIO OKAZAKI ◽  
RYOZO TOEI

2017 ◽  
Vol 6 (1) ◽  
pp. 148-156
Author(s):  
P. Indhumathi ◽  
S. Sathiyaraj ◽  
U. S. Shoba ◽  
P. S. Syed Shabudeen ◽  
C. Jayabalakrishnan

Adsorption is a unique process for the removal of pollutants from water and wastewater since the process is cost effective, easily adoptable and environmentally compatible. The micro algae are a promising way to produce a useful adsorbent for Thorium (VI) removal from aqueous solution. The specific surface area of the microalgae was determined and its properties studied by scanning electron microscopy (SEM). Adsorptive removal of Thorium (VI) from aqueous solution on micro algae has been studied under varying conditions of agitation time, metal ion concentration, adsorbent dose and pH to assess the kinetic and equilibrium parameters. Adsorption equilibrium was obtained in 120 min for 20 to 120 mg/L of Thorium (VI) concentrations. The Langmuir, Freundlich, Temkin, Redlich-Peterson isotherm models, kinetic models and thermodynamic models were found to provide an excellent fitting of the adsorption data. The adsorption capacity of thorium 91.73% maximum percent removal in thorium at pH 3. This adsorbent was found to be effective and economically attractive.


2013 ◽  
Vol 9 (1) ◽  
pp. 1822-1836
Author(s):  
Keon Sang Ryoo ◽  
Jong-Ha Choi ◽  
Yong Pyo Hong

The present study is to explore the possibility of utilizing granular activated charcoal (GAC) for the removal of total phosphorous (T-P) and total nitrogen (T-N) in aqueous solution. Batch adsorption studies were carried out to determine the influences of various factors like initial concentration, contact time and temperature. The adsorption data showed that GAC has a similar adsorption capacity for both T-N and T-P. The adsorption degree of T-N and T-P on GAC was highly concentration dependent. It was found that the adsorption capacity of GAC is quite favorable at a low concentration. At concentrations of 1.0 mg L-1 of T-P and 2.0 mg L-1 of T-N, approximately 97 % of adsorption was achieved by GAC. The equilibrium data were fitted well to the Langmuir isotherm model. The pseudo-second-order kinetic model appeared to be the better-fitting model because it has higher R2 compared with the pseudo-first-order and intra-particle kinetic model. The theoretical adsorption equilibrium qe,cal from pseudo-second-order kinetic model were relatively similar to the experimental adsorption equilibrium qe,exp. To evaluate the effect of thermodynamic parameters at different temperatures, the change in free energy ΔG, the enthalpy ΔH and the entropy ΔS were estimated. Except for adsorption of T-P at 278 K, the ΔG values obtained were all negative at the investigated temperatures. It indicates that the present adsorption system occurs spontaneously. The adsorption process of T-N by GAC was exothermic in nature, whereas T-P showed endothermic behavior. In addition, the positive values of ΔS imply that there was the increase in the randomness of adsorption of T-N and T-P at GAC-solution interface.  


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