scholarly journals Adsorption Isotherm Studies of Chromium (VI) from Aqueous Solutions Using Jordanian Pottery Materials

2012 ◽  
Vol 1 ◽  
pp. 116-125 ◽  
Author(s):  
Khaldoun Al-Sou’od
2014 ◽  
Vol 353 ◽  
pp. 33-38
Author(s):  
Rafique Ullah ◽  
Biplob Kumer Deb ◽  
Mohammad Yousuf Ali Mollah

Chromium (VI) is known to be carcinogenic to humans and thus it is important to ensure the removal of Chromium (VI) from aqueous solutions and industrial effluents. The present study introduces a good alternative method for Cr (VI) removal from aqueous solutions at ambient temperature by adsorption, allowing the development of newer, lower operational cost, and more efficient technology than other processes already in use. Adsorption was found to be dependent on pH and initial concentration of Cr (VI) solution. Results of adsorption studies suggest that pristine iron oxide and silicon (IV) oxide removes 72.10% and 24.73%, respectively. The iron oxide – silicon (IV) oxide composite, prepared in this work, removes 93.88% Cr (VI) in 20 minutes from aqueous solution at an initial concentration of 50 mgL-1at pH 4.8 ± 0.2. The effect of concentration, contact time, adsorbent dose and solution pH on the adsorption of Cr (VI) were studied in detail in batch experiments. Studies of the sorption kinetics shows that equilibrium adsorption was attained in 20 minutes depending on other experimental conditions. The kinetic data justified Lagergren’s first-order kinetic equation. Adsorption isotherm study showed that the results fulfilled the Langmuir Model of adsorption isotherm. The maximum adsorption (98.28%) was recorded at pH 3 in 90 minutes for the initial Cr (VI) concentration of 50 mg L-1. Therefore, it can be concluded that iron oxide – silicon (IV) oxide composite is a potential adsorbent for adsorption of Cr (VI) from aqueous solution.


2009 ◽  
Vol 172 (2-3) ◽  
pp. 1527-1531 ◽  
Author(s):  
Esthela Ramos-Ramírez ◽  
Norma L. Gutiérrez Ortega ◽  
Cesar A. Contreras Soto ◽  
Maria T. Olguín Gutiérrez

2012 ◽  
Vol 9 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Baghdad Science Journal

Equilibrium adsorption isotherm for the removal of trifluralin from aqueous solutions using ? –alumina clay has been studied. The result shows that the isotherms were S3 according Giels classification. The effects of various experimental parameters such as contact time, adsorbent dosage, effect of pH and temperature of trifluralin on the adsorption capacities have been investigated. The adsorption isotherms were obtained by obeying freundlich adsorption isotherm with (R2 = 0.91249-0.8149). The thermodynamic parameters have been calculated by using the adsorption process at five different temperature, the values of ?H, ?G and ?S were (_1.0625) kj. mol-1, (7.628 - 7.831) kj.mol-1 and (_2.7966 - _2.9162) kg. k-1. mol-1 respectively. The kinetic study of adsorption process has been studied depending on three kinetic equations: 1- Allergen equation 2- Morris –weber eguation 3- Reichenberg eguation. In general, the result shows the isotherm were on ?- alumina according to Giels classification.? –alumina and thermodynamic


Author(s):  
Abdelhamid Addala ◽  
Moussa Boudiaf ◽  
Maria Elektorowicz ◽  
Embarek Bentouhami ◽  
Yacine Bengeurba

Abstract Under varied conditions, the IRC 718 ion-exchange resin is used to extract chromium (VI) ions from aqueous solutions. On chromium (VI) removal effectiveness, the effects of adsorption dosage, contact time, beginning metal concentration, and pH were examined. The batch ion exchange process reached equilibrium after around 90 minutes of interaction. With an initial chromium (VI) concentration of 0.5 mg/dm3, the pH-dependent ion-exchange mechanism revealed maximal removal in the pH 2.0–10 range . The adsorption mechanism occurs between Cr(VI) determined as the electron acceptor, and IRC 718 determined as the electron donor. The equilibrium ion-exchange potential and ion transfer quantities for Amberlite IRC 718 were calculated using the Langmuir adsorption isotherm model. The overall ion exchange capacity of the resin was determined to be 187.72 mg of chromium (VI)/g of resin at an ideal pH of 6.0.


2010 ◽  
Vol 7 (1) ◽  
pp. 745-756
Author(s):  
Baghdad Science Journal

The subject of this research involves studying adsorption to remove hexavalent chromium Cr(VI) from aqueous solutions. Adsorption process on bentonite clay as adsorbent was used in the Cr(VI) concentration range (10-100) ppm at different temperatures (298, 303, 308 and 313)K, for different periods of time. The adsorption isotherms were obtained by obeying Langmuir and Freundlich adsorption isotherm with R2 (0.9921-0.9060) and (0.994-0.9998), respectively. The thermodynamic parameters were calculated by using the adsorption process at four different temperatures the values of ?H, ?G and ?S was [(+6.582 ? +6.547) kJ.mol-1, (-284.560 ? -343.070) kJ.mol-1 and (+0.977 ? +1.117) kJ.K-1.mol-1] respectively. This data indicates the spontaneous sorption process. The kinetic study of adsorption process was studied depending on three kinetic equations: 1- Lagergren equation 2- Morris-Weber equation 3- Reichenberg equation


2010 ◽  
Vol 16 (1-3) ◽  
pp. 393-401 ◽  
Author(s):  
K. Rouibah ◽  
A.-H. Meniai ◽  
L. Deffous ◽  
M. Bencheikh Lehocine

2004 ◽  
Vol 2 (1-2) ◽  
pp. 1-7 ◽  
Author(s):  
Ismael Acosta R. ◽  
Xöchitl Rodríguez ◽  
Conrado Gutiérrez ◽  
Ma. de Guadalupe Moctezuma

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