scholarly journals Adsorption efficiency, thermodynamics and kinetics of Schiff base-modified nanoparticles for removal of heavy metals

2016 ◽  
Vol 13 (7) ◽  
pp. 1707-1722 ◽  
Author(s):  
M. K. Moftakhar ◽  
M. R. Yaftian ◽  
M. Ghorbanloo
2013 ◽  
Vol 12 (3) ◽  
pp. 239-247

The removal of heavy metals from wastewaters is a matter of paramount importance due to the fact that their high toxicity causes major environmental pollution problems. One of the most efficient, applicable and low cost methods for the removal of toxic metals from aqueous solutions is that of their adsorption on an inorganic adsorbent. In order to achieve high efficiency, it is important to understand the influence of the solution parameters on the extent of the adsorption, as well as the kinetics of the adsorption. In the present work, the adsorption of Cu(II) species onto TiO2 surface was studied. It was found that the adsorption is a rapid process and it is not affected by the value of ionic strength. In addition, it was found that by increasing the pH, the adsorbed amount of Cu2+ ions and the value of the adsorption constant increase, whereas the value of the lateral interaction energy decreases.


2018 ◽  
Vol 77 (10) ◽  
pp. 2355-2368 ◽  
Author(s):  
Khalida Naseem ◽  
Zahoor H. Farooqi ◽  
Muhammad Z. Ur Rehman ◽  
Muhammad A. Ur Rehman ◽  
Robina Begum ◽  
...  

Abstract This review is based on the adsorption characteristics of sorghum (Sorghum bicolor) for removal of heavy metals from aqueous media. Different parameters like pH, temperature of the medium, sorghum concentration, sorghum particle size, contact time, stirring speed and heavy metal concentration control the adsorption efficiency of sorghum biomass for heavy metal ions. Sorghum biomass showed maximum efficiency for removal of heavy metal ions in the pH range of 5 to 6. It is an agricultural waste and is regarded as the cheapest biosorbent, having high adsorption capacity for heavy metals as compared to other reported adsorbents, for the treatment of heavy metal polluted wastewater. Adsorption of heavy metal ions onto sorghum biomass follows pseudo second order kinetics. Best fitted adsorption isotherm models for removal of heavy metal ions on sorghum biomass are Langmuir and Freundlich adsorption isotherm models. Thermodynamic aspects of heavy metal ions adsorption onto sorghum biomass have also been elaborated in this review article. How adsorption efficiency of sorghum biomass can be improved by different physical and chemical treatments in future has also been elaborated. This review article will be highly useful for researchers working in the field of water treatment via biosorption processing. The quantitative demonstrated efficiency of sorghum biomass for various heavy metal ions has also been highlighted in different sections of this review article.


Author(s):  
Celestin Defo ◽  
Ravinder Kaur

Adsorption kinetics of Ni, Cr, and Pb on gravels collected from constructed wetland was studied at varied metal concentrations and contact period for estimating the removal of heavy metals from wastewater. Batch experiments were conducted by shaking 120 ml of metal solutions having 5 concentration levels each of Ni (1.0, 2.0, 3.5, 5.0 and 6.0 mg l-1), Cr (1.0, 2.0, 3.0, 4.5 and 6.0 mg l-1), and Pb (1.0, 3.0, 6.0, 8.0 and 12.0 mg l-1) with 50 g of gravels for as function of time. Adsorption of Ni, Cr, and Pb on gravels ranged from 34.8 to 47.2, 42.7-54.9, and 47.5-56.9%, indicating their removal in the order: Pb > Cr > Ni. Freundlich model showed a good fit for Ni and Cr (R2>0.9) while Langmuir model fitted better for Pb (R2= 0.7). The pseudo-second-order model showed the best fit to simulate the adsorption rates of these metals on gravel.


2018 ◽  
Vol 62 (2) ◽  
Author(s):  
Erika Bustos ◽  
Irma Robles ◽  
Yamir Bandala ◽  
Juan Manríquez

<p>The presence of mercury in soils, like other heavy metals, is associated with organic matter and minerals. Mercury deposited in soils is mainly in its oxidized form Hg2+. The adsorption of Hg (II) from aqueous solution into Ca-bentonite was studied. Adsorption percentage was determined as a function of shaking time and temperature to study the thermodynamics and kinetics of Hg (II) adsorption on Ca-bentonite, which was simulated using the MINSQ and GAUSSIAN 09 programs.</p>


2021 ◽  
Vol 19 (2) ◽  
pp. 31-37
Author(s):  
Layth S. Jasim ◽  
Aseel M. Aljeboree

In this Study, hydrogel P(CH/AA-co-AM) was prepared, identification and utilized as an efficient absorbent to eliminate Cr (III) and Cd (II) ions from the aqueous solution. The adsorption of these ions follows Freundlich isotherms. Due to greater activity surface of the hydrogel in adsorption of the contaminants, they can be utilized for elimination of the mentioned ions from water. Therefore, we characterized structural, surface and thermal properties of the prepared materials with technique: TGA, FE-SEM and FT-IR. Moreover, we implemented the kinetics of sorption with regard to the amounts of the metal sorbet at distinct time intervals and thus examined the modeling of the isotherm and kinetic curves. Finally, we computed the reaction order as well as rate constant.


Sign in / Sign up

Export Citation Format

Share Document