scholarly journals Generation-3 Polyamidoamine Dendrimer-Silica Composite: Preparation and Cd(II) Removal Capacity

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Augustus N. Ebelegi ◽  
Nimibofa Ayawei ◽  
Azibaola K. Inengite ◽  
Donbebe Wankasi

Generation-3 polyamidoamine (PAMAM) dendrimer was implanted on silica to produce a very good adsorbent (G-3 PAMAM-SGA). The composite was characterized and used for the removal of Cd(II) ions from aqueous solution. Kinetic data fit the Lagergren pseudo-second-order model and also follow the intraparticle diffusion kinetic model to an extent, which is an indication that the sorption process is controlled by both mechanisms: intraparticle/film layer and adsorption inside the pores/crevices of the composite. Equilibrium sorption data of Cd(II) on G-3 PAMAM-SGA fit the Freundlich isotherm (R2 = 0.9993) which is indicative of multilayered adsorption that occurred on heterogeneous surfaces. The ΔG° values for all temperatures studied were negative, which indicated a spontaneous and feasible process. The result implies that G-3 PAMAM-SGA is a promising adsorbent for microscale scavenging of Cd(II) ions in aqueous solutions.

2013 ◽  
Vol 726-731 ◽  
pp. 2736-2741
Author(s):  
Ming Da Liu ◽  
Ge Tian ◽  
Liang Jie Zhao ◽  
Yao Sheng Wang ◽  
Lei Guo ◽  
...  

Five blast-furnace slags were used as adsorbents to remove Pb (II) from aqueous solution. Kinetic studies showed that the sorption process was best described by pseudo-second-order model. Among Langmuir, Freundlich and Temkin isotherms, the Freundlich isotherm had a better fit with the simulation of the adsorption of Pb (II).


Molekul ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 28
Author(s):  
Mohammad Jihad Madiabu ◽  
Joko Untung ◽  
Imas Solihat ◽  
Andi Muhammad Ichzan

The research aims to investigate feasibility eggshells as potential adsorbent to remove copper(II) ions from aqueous solution. Eggshells powder was characterized using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. Effect of copper(II) initial concentration, adsorbent dosage, and contact time have conducted. The optimum adsorption condition obtained when 0.7 g eggshells applied to 50 mg/L copper(II) solution for 50 minutes. The maximum percentage of copper(II) removal was exceeded more than 85%. Langmuir and Freundlich isotherm model were applied to describe the equilibrium adsorption. Copper(II) kinetics sorption process was fitted to pseudo-second order model with a rate constant equal to 0.516 g/mg.min. The results clearly exhibit that eggshells powder can be effectively used to remove copper(II) ions from aqueous solutions.


2013 ◽  
Vol 15 (4) ◽  
pp. 542-550 ◽  

<p>This study aimed to evaluate the sorption capability of an inexpensive and easily available Moroccan clay, called locally Ghassoul, to remove Rhodamine B (Rh-B) from aqueous solution. Experimental results showed that the equilibrium sorption data fitted well with the Langmuir isotherm and the monolayer sorption capacity was estimated as 448 mg g-1 at 298K. Kinetic analyses showed that the sorption rate was more accurately represented by a pseudo second-order model. The intra-particle diffusion was involved in the overall rate of the sorption process but it was not the only rate-controlling step. The calculated thermodynamics parameters showed the spontaneous and the endothermic nature of the sorption process. The activation energy found to be 5.36 kJ mol-1 could indicate a physical sorption process. The obtained results confirmed the applicability of this clay as an efficient and economical adsorbent for cationic dyes from contaminated water.</p>


2019 ◽  
Vol 233 (9) ◽  
pp. 1275-1292 ◽  
Author(s):  
Atta ul Haq ◽  
Muhammad Rasul Jan ◽  
Jasmin Shah ◽  
Maria Sadia ◽  
Muhammad Saeed

Abstract The presence of heavy metals in water causes serious problems and their treatment before incorporating into the water body is a challenge for researchers. The present study was conducted to compare the sorption study of Ni (II) using silica gel, amberlite IR-120 and sawdust of mulberry wood in batch system under the influence of pH, initial Ni (II) concentration and contact time. It was observed that sorption process was depending upon pH and maximum sorption was achieved at pH 7.0. Kinetic data were well fitted into pseudo-second order kinetic model due to high R2 values and closeness of experimental sorption capacity and calculated sorption capacity of pseudo-second order. Isotherms study showed that Langmuir is one of the most suitable choices to explain sorption data due to high R2 values. The monolayer sorption capacities of silica gel, amberlite IR-120 and sawdust were found to be 33.33, 25.19, and 33.67 mg g−1, respectively. Desorption study revealed that NaCl is one of the most appropriate desorbent. It may be concluded from this study that sawdust is a suitable sorbent due to low cost, abundant availability and recycling of the materials for further study.


2011 ◽  
Vol 233-235 ◽  
pp. 439-443
Author(s):  
Ying Hua Song ◽  
Sheng Ming Chen

The sorption of eosin by peanut husk, which was chemically modified by formaldehyde in acidic medium was studied with variation in the parameters of contact time, pH, initial eosin concentration and temperature. They were used for equilibrium sorption uptake studies with eosin. The results indicate that sorption equilibrium could be well described by the Freundlich isotherm equation. The sorption followed the pseudo-second order model. The mass transfer model as intraparticle diffusion was applied to the experimental data to examine the mechanisms of the rate controlling step. It was found that the intraparticle diffusion is becoming the significant controlling step under the experimental conditions. The thermodynamic constants of the sorption process were also evaluated, which suggest an endothermic physical sorption process which runs spontaneously.


2011 ◽  
Vol 6 (3) ◽  
pp. 155892501100600 ◽  
Author(s):  
Fang Li ◽  
Chunmei Ding

Different degree of deacetylation (DD) chitosan was prepared and used for the removal of a Reactive black M-2R (RBM) from aqueous solution. The effects of temperature (298 K~323 K), chitosan dosage, degree of deacetylation on RBM removal were investigated. The adsorption equilibrium was reached within one hour. In order to determine the adsorption capacity, the sorption data were analyzed by using linear form of Langmuir, Freundlich and Tempkin isotherm equation. Langmuir equation shows higher conformity than the other two equations. From the kinetic experiment data, it was found that the sorption process follows the pseudo-second-order kinetic model. Activation energy value for sorption process was found to be 58.28 kJ mol-1. Chitosan with 66% deacetylation degree (DD) exhibited good adsorption performance for RBM. In order to determine the interactions between RBM and chitosan, FTIR analysis was also conducted.


2017 ◽  
Vol 2 (1) ◽  
pp. 13-26
Author(s):  
Tengku Khamanur Azma Tg. Mohd Zamri ◽  
Mimi Sakinah Abd Munaim ◽  
Zularisam Ab Wahid

Natural dye extracted from the rhizome of Curcuma longa L. were applied to bamboo yarns using exhaustion dyeing process. This study investigates the dyeing behaviour of Curcumin; the major color component isolated from rhizomes of Curcuma longa L.on bamboo yarn. Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich isotherm models were used to test the adsorption process of curcumin on bamboo yarn. Comparison of regression coefficient value indicated that the Freundlich isotherm most fitted to the adsorption of curcumin onto bamboo yarn. Furthermore, the kinetics study on this research fitted the pseudo-second order model which indicates that the basis of interaction was chemical adsorption.


2012 ◽  
Vol 14 (2) ◽  
pp. 1-8 ◽  
Author(s):  
S. Ghadiri ◽  
R. Nabizadeh ◽  
A. Mahvi ◽  
S. Nasseri ◽  
A. Mesdaghinia ◽  
...  

Potential of granulated modified nanozeolites Y for MTBE removal from aqueous solutions: Kinetic and isotherm studies Adsorption of methyl tert-butyl ether (MTBE) from aqueous solutions by granulated modified nanozeolites Y was investigated. Nanozeolite Y powders were converted into granulated zeolites and subsequently modified with two cationic surfactants (20 mmol/dm3), to be used as adsorbent. Granulated nanozeolites were characterized by BET surface area analysis, elemental analysis and X-ray diffractometer. -Hexade-cyltrimethylammonium (HDTMA-Cl) modified granulated zeolite had more effective performance than N-cetylpyridinium bromide (CPB) modified granulated zeolite. The most conventional adsorption isotherms and kinetic models were applied to describe MTBE adsorption and reaction dynamic, respectively. The equilibrium sorption data fitted the Langmuir 2 isotherm model and the kinetic study was followed the pseudo-second-order model. The maximum adsorption capacities for HDTMA-Cl modified zeolite and CPB modified granulated zeolite were 333.33 and 142.8 mg/g, respectively as calculated by the Langmuir model. This study demonstrated that the removal of mtbe by granulated modified nanozeolites Y is a promising technique.


Author(s):  
Jurgita Seniūnaitė ◽  
Rasa Vaiškūnaitė ◽  
Kristina Bazienė

Research studies on the adsorption kinetics are conducted in order to determine the absorption time of heavy metals on coffee grounds from liquid. The models of adsorption kinetics and adsorption diffusion are based on mathe-matical models (Cho et al. 2005). The adsorption kinetics can provide information on the mechanisms occurring be-tween adsorbates and adsorbents and give an understanding of the adsorption process. In the mathematical modelling of processes, Lagergren’s pseudo-first- and pseudo-second-order kinetics and the intra-particle diffusion models are usually applied. The mathematical modelling has shown that the kinetics of the adsorption process of heavy metals (copper (Cu) and lead (Pb)) is more appropriately described by the Lagergren’s pseudo-second-order kinetic model. The kinetic constants (k2Cu = 0.117; k2Pb = 0,037 min−1) and the sorption process speed (k2qeCu = 0.0058–0.4975; k2qePb = 0.021–0.1661 mg/g per min) were calculated. After completing the mathematical modelling it was calculated that the Langmuir isotherm better reflects the sorption processes of copper (Cu) (R2 = 0.950), whilst the Freundlich isotherm – the sorption processes of lead (Pb) (R2 = 0.925). The difference between the mathematically modelled and experimen-tally obtained sorption capacities for removal of heavy metals on coffee grounds from aqueous solutions is 0.059–0.164 mg/l for copper and 0.004–0.285 mg/l for lead. Residual concentrations of metals in a solution showed difference of 1.01 and 0.96 mg/l, respectively.


2013 ◽  
Vol 726-731 ◽  
pp. 2380-2383
Author(s):  
Li Xia Li ◽  
Xin Dong Zhai

Modified bentonite was used as adsorbent for the methylene blue adsorption in a batch process. Experimental results show that the adsorption kinetics is well described by pseudo-second-order model and the equilibrium data was better represented by the Freundlich isotherm model. The results revealed that the modified bentonite has the potential to be used as a good adsorbent for the removal of methylene blue from aqueous solutions.


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