scholarly journals DETERMINATION OF HEXAVALENT CHROMIUM ADSORPTION KINETICS AND EQUILIBRIUM ISOTHERMS IN AQUEOUS SOLUTIONS CONTAINING ACTIVATED COCONUT SHELL CHARCOAL

Author(s):  
A. C. de MENESES ◽  
A. D. da LUZ ◽  
C. da LUZ ◽  
G. ZIN
2020 ◽  
Vol 36 (05) ◽  
pp. 915-922
Author(s):  
Sunil Kumar ◽  
Rajesh Dhankhar

This study examined the utilization of Raw Eichhornia crassipes (REC) biomass to exclude the hexavalent chromium heavy metal from synthetic liquid for determination of sorption isotherm, kinetics and thermodynamic parameters of adsorption during the batch experiment process. The effect of adsorbent doses, agitation time and temperature on sorption capacity was studied. The plot qt versus t1/2 determined the intra-particle diffusion effect, which was not passing from the origin of plot indicated that apart from intra-particle diffusion some other mechanism also involved in this study. Freundlich isotherm better fitted as compared to Langmuir isotherm in the present study. The kinetics study show that pseudo-second-order better followed by REC adsorbent. At 293 K temperature, Δ Go negative value suggested that process favoured the sorption and spontaneous in nature, but at higher temperatures, positive values Δ Go confirmed the non-spontaneous nature of adsorption. It is concluded that Eichhornia crassipes dead biomass has the potential to treat wastewaters as an adsorbent.


RSC Advances ◽  
2016 ◽  
Vol 6 (42) ◽  
pp. 35332-35339 ◽  
Author(s):  
Dan Chen ◽  
Xuelian Xiao ◽  
Kai Yang

In this work, a novel adsorbent derived from waste eggshell (ES) was used for phosphate and hexavalent chromium adsorption.


2020 ◽  
Vol 14 ◽  
pp. 100300 ◽  
Author(s):  
Haniyeh Jalayeri ◽  
Paolo Aprea ◽  
Domenico Caputo ◽  
Antonio Peluso ◽  
Francesco Pepe

2014 ◽  
Vol 10 (6) ◽  
pp. 2786-2795
Author(s):  
Ahlafi Hammou ◽  
H. MOUSSOUT ◽  
MY. S. SLIMANI ◽  
F. BOUKHLIFI ◽  
I. DAOU

The present work focuses on the study of the application of abundant and less expensive materials such as chitosan and bentonite/chitosan biocomposite in the removal of hexavalent chromium. Spectroscopic analysis like techniques FTIR, XRD and BET have been used to characterize the adsorbents. The data indicate that the adsorption of chromium proceeds kinetically according to a pseudo-second order model on both samples and the apparent activation energy (Ea) have been measured to be 22.9 kJ.mol−1 and 84.4 kJ.mol−1 for chitosan and 5%Bt/CS, respectively. The adsorption isotherm experiments show that the adsorption capacity depends on the studied chromium adsorption temperature. It has been found that the data could be well described by the Langmuir as well as the Freundlich models. Thermodynamic parameters (i.e., change in the free energy (DG°), the enthalpy (DH°), and the entropy (DS°) have been also, evaluated.


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