scholarly journals STUDY ON THE ADSORPTION PROPERTIES OF NOVEL CALIX[6]ARENE POLYMERS FOR HEAVY METAL CATIONS

2012 ◽  
Vol 12 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Susy Yunita Prabawati ◽  
Jumina Jumina ◽  
Sri Juari Santosa ◽  
Mustofa Mustofa ◽  
Keisuke Ohto

A research has been conducted to investigate the capability of a series of novel calix[6]arenes-based polymers: poly-monoallyloxycalix[6]arene (2a), poly-monoallyloxypenta-estercalix[6]arene (2b) and poly-monoallyloxypenta-acidcalix[6]arene (2c) for trapping of heavy metal cations such as Cd(II), Cu(II) and Cr(III). The existence of active hydroxy group (-OH) and with a tunnel-like structure of the polymers, caused the polymers can be used as adsorbents for heavy metals. The adsorption process was carried out in batch method in the variation of acidity (pH), contact time and initial concentration of metal ions. The results showed that the amount of adsorbed metal increased with the increasing of the pH of metal solution. For these three polymers, the amount of metal ions Cd(II), Cu(II) and Cr(III) adsorbed was optimum at pH 7, 6 and 5 respectively. The optimum contact time for Cd(II) and Cu(II) was 120 min, while that for Cr(III) was 60 min. Study of the adsorption kinetics showed that the adsorption of Cd(II), Cu(II) and Cr(III) using polymer 2a followed kinetics model of Ho. For adsorbent 2b and 2c, the adsorption kinetics of Cd(II) and Cr(III) also followed kinetics model of Ho while for the Cu(II) followed Lagergren kinetic models. Isothermal studies showed that the adsorption of metal ions on all adsorbents tend to follow the Langmuir isotherm. The adsorption energies of the three adsorbents were higher than 23 kJ/mole and polymer 2c has the largest adsorption capacity for Cr(III).

2020 ◽  
Vol 5 (2) ◽  
pp. 94
Author(s):  
Susy Yunita Prabawati ◽  
Jumina Jumina ◽  
Sri Juari Santosa ◽  
Mustofa Mustofa

This research aims to examine the capability of poly-37,40-diallyl-38,39,41,42,-tetrahydroxy-calix[6]arenes as adsorbent for heavy metal cations such as Cd(II), Cr(III) and Cu(II). The adsorption process was carried out by batch method in the variation of acidity (pH), contact time and initial concentration of metal ions. The adsorption kinetics and adsorption isotherms were also studied. The results of this research showed that the amount of adsorbed metal increased with the increasing of the pH of metal solution. The amount of metal ions Cd(II) and Cr(III) adsorbed was optimum at pH 5, while for metal ion Cu(II) was optimum at pH 4. The optimum contact time for Cd(II), Cr(III) and Cu(II) was 60; 30; and 180 minutes, respectively. The study of adsorption kinetics showed that the adsorption of Cd (II), Cr (III) and Cu (II) metal ions using this adsorbent followed kinetics model of Ho. Isothermal studies showed that the adsorption of the three metal ions tends to follow the Langmuir isotherm. The adsorption capacities of Cd (II), Cr (III) and Cu (II) metal ions with poly-37,40-diallyl-38,39,41,42,-tetrahydroxycalix[6]arenes were 7.06; 14.72 and 38.45 µmol/g, respectively.  


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2150 ◽  
Author(s):  
M.A. Martín-Lara ◽  
M. Calero ◽  
A. Ronda ◽  
I. Iáñez-Rodríguez ◽  
C. Escudero

Bisphenol A (BPA) is an extensively produced and consumed chemical in the world. Due to its widespread use, contamination by this pollutant has increased in recent years, reaching a critical environmental point. This work investigates the feasibility of bisphenol A adsorption from industrial wastewater solutions, testing the reduction of bisphenol A in synthetic solutions by a commercial activated carbon, AC-40, in batch mode. Besides, mixtures of bisphenol A and different heavy metal cations were also studied. So far, no works have reported a complete study about bisphenol A removal by this activated carbon including the use of this material to remove BPA in the presence of metal cations. First, adsorption experiments were performed in batch changing pH, dose of adsorbent, initial bisphenol A concentration and contact time. Results showed greater retention of bisphenol A by increasing the acidity of the medium. Further, the percentage of bisphenol A adsorbed increased with increasing contact time. The selected conditions for the rest of the experiments were pH 5 and a contact time of 48 h. In addition, an increase in retention of bisphenol A when the dose of adsorbent increased was observed. Then, specific experiments were carried out to define the kinetics and the adsorption isotherm. Equilibrium data were adequately fitted to a Langmuir isotherm and the kinetics data fitted well to the pseudo-second-order model. The maximum adsorption capacity provided by Langmuir model was 94.34 mg/g. Finally, the effect of the presence of other heavy metals in water solution on the adsorption of bisphenol A was analyzed. Binary tests revealed competition between the adsorbates and a significant selectivity toward bisphenol A. Finally, the study of the adsorption performance in three consecutive adsorption–desorption cycles showed efficiencies higher than 90% in all cycles, indicating that the activated carbon has good reusability.


2010 ◽  
Vol 61 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Slávka Andrejkovičová ◽  
Martin Pentrák ◽  
L'uboš Jankovič ◽  
Peter Komadel

Sorption of heavy metal cations on rhyolitic and andesitic bentonites from Central SlovakiaThe main purpose of this work was to determine adsorption characteristics of heavy metal cations on two Slovak bentonites. Adsorption of Pb2+, Zn2+, Cu2+and Cd2+on Jelšový Potok (JP) and Lieskovec (L) bentonites was studied by the batch equilibration technique using solutions of different concentrations. Higher smectite content (81 mass %) and higher cation exchange capacity (CEC) (105 mmol M+/100 g) of JP bentonite cause higher adsorption of all heavy metals in comparison with L bentonite. JP adsorbed heavy metals in the order Pb2+» Cd2+> Zn2+> Cu2+while sorption on L was slightly different, Pb2+» Cd2+> Cu2+≥ Zn2+. The Freundlich model of adsorption is more appropriate for adsorption of Pb2+and Cd2+while lower uptake of Cu2+and Zn2+is better described by the Langmuir model. Negative ΔG° values indicate that the adsorption process of all cations on both bentonites is feasible, spontaneous and exothermic. The decrease in thed001spacings from 14.8-14.9 Å in natural dominantly Ca2+-saturated samples to 13.2-12.6 Å for both bentonites saturated with four heavy metal cations shows the effect of less hydrated exchangeable cations on interlayer spacing. Jelšový Potok bentonite of higher montmorillonite content and greater CEC is the more effective candidate for removal of Pb2+, Zn2+, Cu2+and Cd2+from waste water than Lieskovec bentonite.


2020 ◽  
Vol 23 (10) ◽  
pp. 370-376
Author(s):  
Thamrin Azis ◽  
La Ode Ahmad ◽  
Keke Awaliyah ◽  
Laode Abdul Kadir

Research on the equilibrium and adsorption kinetics of methylene blue dye using tannin gel from the Tingi tree (Ceriops tagal) has been carried out. This study aims to determine the capacity and adsorption kinetics of tannin gel against methylene blue dye. Several parameters, such as the effect of contact time, pH, and methylene blue dye concentration on adsorption, were also studied. Based on the research results, the optimum adsorption process is a contact time of 30 minutes and a pH of 7. The adsorption capacity increased to a concentration of 80 mg/L with a maximum adsorption capacity (qm) of 49.261 mg/g. The adsorption process follows the pseudo-second-order adsorption kinetics model and the Langmuir isotherm model.


RSC Advances ◽  
2014 ◽  
Vol 4 (86) ◽  
pp. 46122-46125 ◽  
Author(s):  
Kun Yang ◽  
Wei Wei ◽  
Long Qi ◽  
WenHao Wu ◽  
QingFeng Jing ◽  
...  

We observed that the removal of metal ions with engineered nanomaterials could be largely attributed to precipitation by forming metal hydroxyl precipitates rather than adsorption, implying that ENMs cannot be superior adsorbents.


2018 ◽  
Vol 13 (1) ◽  
pp. 155892501801300
Author(s):  
Xuchen Tao ◽  
Quan Feng ◽  
Hui He

In order to utilize the adsorption selectivity of calixarenes towards heavy metal ions, calixarene functionalized polyimide (Calix-PI) fibers were prepared by three main synthesis procedures including preparation of the calixarene polyamide acid (Calix-PAA) spinning solution via amidation, fabrication of the Calix-PAA fibers by electrospinning, and preparation of the Calix-PI fibers via thermal imidization on the Calix-PAA fibers. The Calix-PI fibers were characterized by Fourier transform infrared spectroscopy, scanning electronic microscopy and thermogravimetric analysis. The Calix-PI fibers display selective adsorption on Pb(II), which is fit with the pseudo-second-order adsorption kinetics model and the Freundlich adsorption isothermal model. The rate constant of the pseudo-second-order adsorption kinetics model and the maximum Pb(II) uptake have all been calculated. The practical adsorption of Pb(II) on the Calix-PI fibers is mainly attributed to the monolayer chemical adsorption and slightly depended on the physical adsorption.


RSC Advances ◽  
2015 ◽  
Vol 5 (2) ◽  
pp. 1350-1358 ◽  
Author(s):  
Monica Caselli

ESAM as fluorescent probes for Hg(ii) ions were developed. The adsorption process involved in analyte-solid probe interaction was studied by monitoring fluorescence quenching.


2019 ◽  
Vol 57 (1) ◽  
pp. 66-71
Author(s):  
Alsu S. Ibragimova ◽  
◽  
Alla Yu Krynitskaya ◽  
Elena V. Petukhova ◽  
Pavel P. Sukhanov ◽  
...  

The content of cadmium, mercury, zinc and cuprum ions in extracts of Eleutherococcus prickly root powder was determined by stripping voltammetry. The content of Zn2+ cations in the aqueous extracts of the plant adaptogen was below the detection limit for the analysis method used. The concentration of ions Cd2+, Pb2+ in aqueous extracts it was less than 0.0002 mg/kg. The amount of cuprum ions did not exceed 2.6 mg/kg. Consequently, the concentrations of heavy metal cations are below the MPC level (maximum permissible concentration), which allows us to speak about the toxicological safety of the plant material studied. Increasing the maceration temperature from 23 to 40 °C reduces the efficiency of the process. The possible causes of this phenomenon are discussed. The source of raw materials does not have a significant effect on the content of pollutants. For the extraction of plant materials, along with distilled water, tap water can be used, which in its performance meets the standards for the content of heavy metal ions in all areas of the city of Kazan. The maximum value of the total pollution indicator is 4.5 mg/l. It was found in tap water selected in the Vakhitovsky district of the city of Kazan. However the maximum lead content is characteristic of the water selected in the Soviet district of the city. Distillation of water is expected to reduce pollution by pollutants. However complete purification from heavy metal ions does not occur. The most intense distillation is the purification of water from cuprum ions. The minimum amount of pollutants is found in ethanolic extracts of Eleutherococcus root powder. It is obvious that ethanol, as an extractant of heavy metal cations, is less preferable than water.


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