scholarly journals Removal of Radioactive Iodide by Surfactant-Modified Zeolites

2003 ◽  
Vol 21 (4) ◽  
pp. 373-381 ◽  
Author(s):  
Hossein Faghihian ◽  
Akbar Malekpour ◽  
Mohammad G. Maragheh
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Exchangeable Cations ◽  
Natural Zeolites ◽  
Zeolite Surface ◽  
Surfactant Modification ◽  
Liquid Wastes ◽  
Modified Zeolites ◽  
Modified Forms ◽  
Adsorbent Materials

The removal of radionuclides such as 129I and 131I from radioactive liquid wastes was studied. Two natural zeolites were modified with different quaternary alkylammonium ions to replace the exchangeable cations from the zeolite surface and used as adsorbent materials. The quaternary ions used for such purpose were hexadecyltrimethylammonium, tetradecyltrimethylammonium, dodecyltrimethylammonium, tetrabutylammonium and tetramethylammonium, respectively. Some of the modified forms exhibited an adsorption capacity much higher than those of the respective natural samples. In contrast, the adsorption capacity was negligible when tetrabutylammonium and tetramethylammonium ions were used. Adsorption experiments were conducted by batch and continuous experiments, and adsorption isotherms constructed from the data obtained. The effect of interfering anions on the adsorption capacity was also investigated as were the breakthrough behaviours of radioiodide in a column charged with the various adsorbents. Desorption of iodide from the modified zeolites into different solutions was also investigated. It was concluded that, in some cases, surfactant modification was an efficient process for the uptake and immobilization of iodide.

scholarly journals Exploratory study to assess the impact of chitosan /bentonite ratio on the metal removal capacity of chitosan modified bentonite clay

2016 ◽  
Vol 18 (2) ◽  
pp. 437-443 ◽  
Keyword(s):  
Physical Properties ◽  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Exploratory Study ◽  
Metal Removal ◽  
Bentonite Clay ◽  
Settling Rate ◽  
Modified Bentonite ◽  
Removal Capacity ◽  
The Impact

<div> <p>Adsorption is one of the methods that can be used for metal removal. In this study five metals were used cadmium, chromium, lead, copper and Nickel (Cd, Cr, Pb, Cu, and Ni) over a concentration range from 0.8 to about 7 mg l<sup>-1</sup> for each metal. Adsorbents were prepared with increasing chitosan to bentonite ratio from 0 to 0.67 g chitosan/g bentonite. The study showed that adsorption of metals on plain bentonite and chitosan modified bentonite can fit well with Langmuir and Freundlich adsorption isotherms. Furthermore, the bentonite adsorption capacity will decrease with the increase of chitosan/bentonite ratio. This study concluded that bentonite is a good adsorbent. However, the applicability of bentonite as potential adsorbent may be limited by its physical properties such as slow settling rate and difficulty to use it as an adsorbent in adsorption columns. Despite the decrease of maximum theoretical adsorption capacity as a result of chitosan modification, the addition of small amount of chitosan can improve the physical characteristics of bentonite clay to be used as an adsorbent.&nbsp;</p> </div> <p>&nbsp;</p>

scholarly journals Adsorption Studies of Lead by Enteromorpha Algae and Its Silicates Bonded Material

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Hassan H. Hammud ◽  
Ali El-Shaar ◽  
Essam Khamis ◽  
El-Sayed Mansour
Keyword(s):  
Thermal Analysis ◽  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Flow Rate ◽  
Rate Control ◽  
Error Function ◽  
Lead Adsorption ◽  
Nonlinear Methods ◽  
Adsorption Studies ◽  
Flow Rate Control

Lead adsorption by green Enteromorpha algae was studied. Adsorption capacity was 83.8 mg/g at pH 3.0 with algae (E) and 1433.5 mg/g for silicates modified algae (EM). FTIR and thermal analysis of algae materials were studied. Thomas and Yoon-Nelson column model were best for adsorbent (E) and algae after reflux (ER) and Yan model for (EM) with capacity 76.2, 71.1, and 982.5 mg/g, respectively. (ER) and (EM) show less swelling and better flow rate control than (E). Nonlinear methods are more appropriate technique. Error function calculations proved valuable for predicting the best adsorption isotherms, kinetics, and column models.

Adsorption of Cu(II) from Aqueous Solution by Peanut Shell

2011 ◽  
Vol 347-353 ◽  
pp. 1852-1855 ◽  
Author(s):  
Zheng Jun Gong ◽  
Cong Cong Tang ◽  
Cai Yun Sun ◽  
Lu Tang ◽  
Jun Chen
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Batch Adsorption ◽  
Present System ◽  
Peanut Shell ◽  
Optimum Conditions ◽  
Langmuir Adsorption ◽  
Adsorption Data ◽  
Adsorption Intensity

A natural peanut shell was used as adsorbent for removal of Cu(Ⅱ) from aqueous solution. Optimum conditions for the elimination of Cu(Ⅱ) from aqueous solution were established by means of a batch adsorption technique. The applicability of the Langmuir and Freundlich adsorption isotherms for the present system was tested. The Langmuir adsorption capacity Qmax (mg/g) is 39.68 and the equilibrium constant b is 0.00776. The Freundlich adsorption capacity k is 0.978 and adsorption intensity n is 1.65. The goodness of fitness was obtained with the Langmuir and Freundlich adsorption isotherms from the equilibrium adsorption data.

Solar Refrigerator With Efficient Adsorbent

2009 ◽  
Author(s):  
Jessica Trujeque Bolio
Keyword(s):  
Hydrogen Bonds ◽  
Adsorption Capacity ◽  
Environmental Conditions ◽  
Natural Zeolites ◽  
Composite Sorbent ◽  
Humid Climate ◽  
Gaseous State ◽  
Cooling Technology ◽  
Desorption Mechanism ◽  
Efficient Adsorbent

The design a solar-sorption refrigerator to be used in the warm and humid climate of Mexico, the most critical environmental conditions and most demanding climatic zone for cooling technology, requires that the adsorption capacity of the composite sorbent to be characterize. It must be verified that the composite sorbent such as silica gel, calcium chloride and various natural zeolites, with different substances in a gaseous state as sorbate, (water, methanol and ethanol), has hydrogen bonds that can be united and broken easily, measuring the amount of energy required by the sorption-desorption mechanism.

Combined Adsorption Isotherms for Measuring the Adsorption Capacity of Fly Ash in Concrete

2014 ◽  
Vol 2 (4) ◽  
pp. 614-620 ◽  
Author(s):  
Zeyad T. Ahmed ◽  
David W. Hand ◽  
Melanie K. Watkins ◽  
Larry L. Sutter
Keyword(s):  
Fly Ash ◽  
Adsorption Capacity ◽  
Adsorption Isotherms

scholarly journals Adsorpsi Asam Humat pada Zeolit Alam yang Dimodifikasi dengan TiO2

2020 ◽  
Vol 11 (1) ◽  
pp. 43-51
Author(s):  
Upita Septiani ◽  
Fiska Julian Tasari ◽  
Zilfa Zilfa
Keyword(s):  
Humic Acid ◽  
Adsorption Capacity ◽  
Natural Zeolite ◽  
Sol Gel ◽  
Sem Analysis ◽  
Maximum Adsorption Capacity ◽  
Natural Zeolites ◽  
X Ray ◽  
West Sumatra ◽  
Silica Alumina

This research modified natural zeolite with TiO2 synthesized by the sol-gel process which was applied as a humic acid adsorbent. The purpose of this study was to coat natural zeolites with TiO2 to increase the adsorption capacity of natural zeolites as humic acid adsorbents. The natural zeolite powders were obtained from Kabupaten Solok, West Sumatra, based on X-ray Fluorescence (XRF) analysis, the ratio of silica/alumina (Si/Al) was 4.35, indicating that natural zeolite was clinoptilolite zeolite. Scanning Electron Microscopy (SEM) analysis showed natural zeolite has a rough surface with closed pores while zeolite coated with TiO2 (zeolite/TiO2) has a homogeneous, smooth surface with open pore. The results of the Energy Dispersive X-Ray Spectroscopy (EDS) analysis showed that the level of TiO2 was 7.1%, this result showed that TiO2 has been coated on the surface of the zeolite. Natural zeolite and zeolite/TiO2 were applied as humic acid adsorbents. Maximum adsorption capacity of natural zeolites and zeolites/TiO2 were 0.2787 mg/g and 1.199 mg/g, respectively.

scholarly journals PEMANFAATAN ARANG AKTIF SABUT KELAPA SAWIT SEBAGAI ADSOBEN ZAT WARNA SINTETIS REACTIVE RED-120 DAN DIRECT GREEN -26

Alotrop ◽  
2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Melfi Puspita ◽  
M. Lutfi Firdaus ◽  
Nurhamidah Nurhamidah
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Activated Charcoal ◽  
Contact Time ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Analysis Method ◽  
Optimum Conditions ◽  
Coconut Fiber ◽  
Reactive Red 120

The problem of environmental polution caused by waste of batik industry lately is increasing, so it needed a method to overcome that problem. The aim of this study was to determine the ability of activated charcoal from coconut fiber palm in adsorbing Reactive Red-120 and Direct Green-26 dyes in waste of batik along with determining the parameters of isotherms adsorption using UV-Vis Spectrophotometer analysis method. Variations of pH, contact time, adsorbent weight and temperature were carried out as variable to obtain optimum conditions of the adsorption process. The optimum of conditions for Reactive Red-120  occured at pH 3 and a contact time of 30 minutes, while Direct Green-26  occurred at pH 4 and a contact time of 40 minutes, with each adsorbent weight 150 mg and the temperature 30 °C. Adsorption isotherms determined by Freundlich and Langmuir models with maximum adsorption capacity (Qmax) were obtained for the Reactive Red-120  was 400 mg/g, while Direct Green-26 is 169 mg/g. 

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