scholarly journals Adsorption of Copper from aqueous solution by chitosan using molecular imprinting technology

2018 ◽  
Vol 3 (4) ◽  
pp. 141 ◽  
Author(s):  
Sepehr Azizkhani ◽  
Ebrahim Mahmoudi ◽  
Arefeh Emami ◽  
Siti Aslina Hussain ◽  
Abdul Wahab Mohammad

In nature chitosan is a plentiful polymer with high heavy metal ion uptake capacity due to chitosan’s functional groups that chelate with the positive surfaces of heavy metal ions. In this study, epichlorohydrin was used as a crosslink to prepare the copper-imprinted chitosan as a pattern to enable the selectivity property and increase adsorption capacity. The effects of the cross-linker, PH, initial concentration and time were examined in this study to identify the optimum amount of each to remove copper metal ions from waste water by imprinted chitosan. This composite was characterized by Fourier-transform infrared spectroscopy (FTIR) test to determine the existence of copper ions in chitosan crosslinked with epichlorohydrin. Scanning electron microscopy (SEM) tests were also done to compare the surfaces of crosslinked chitosan and the removal of copper by imprinted chitosan. PH adsorption was tested from 3 to 7 and the initial concentration and time investigated were between 10 and 100 mg/l and 0 and 120 minutes respectively. The maximum capacity to adsorb was found to be at PH 7, initial concentration of 100mg/l at 90 minutes with 0.1 gr chitosan. Ultimately, the maximum adsorbent amount achieved for effective Cu(II) removal was 74.37 mg/g.

2020 ◽  
Vol 15 (2) ◽  
pp. 73-85

Poly(4,4′-biphenol oxalate) oligomer was synthesized and characterized by FT-IR, elemental analysis XRD and thermal analysis. The capability of the oligomer to take away Pb(II), Zn(II), Sn(II) and Cu(II) metal ions from aqueous solutions was considered by the known batch and column techniques in terms of concentration, pH value, contact time and temperature. The results indicated that a high initial rate of metal-ion uptake by the oligomer was observed throughout the first 30 minutes, which enlarged slightly amid rising the pH value and then reached its greatest value at pH=5.00 for Pb(II) and Zn(II), pH=4.00 for Cu(II) and pH=6.00 for Sn(II). The oligomer exhibited a high metal-ion uptake capacity to Pb(II) and Zn(II), but a little metal-ion uptake capacity to Cu(II) and Sn(II). Linearized forms of the Langmuir, Freundlich and Dubinin–Radushkevich adsorption isotherms were used to investigate the experimental equilibrium concentration data of Pb(II), Zn(II), Cu(II) and Sn(II). ΔG values demonstrated that the adsorption process of these metal ions on the oligomer is favored while the ΔH values indicated that this process is endothermic. On the other hand, the entropy of the process is positive. In addition to batch experiments, column experiments were performed, where the metal ions were efficiently recovered by treatment of the metal-loaded oligomer with 1.0 M HNO3, 1.0 M HCl and 0.5 M EDTA. The best results were obtained with 1.0 M HNO3 solution.


2012 ◽  
Vol 550-553 ◽  
pp. 2081-2084
Author(s):  
Hai Hong Jia ◽  
Guo Xiang Xu ◽  
Hong Ying Zhou

Experiment was made to study heavy metal ion mining wastewater.The effect of Temperature, pH, Initial concentration, coexisting ions and time on the performance of Nanomaterials were investigated. Results showed that removal efficiency of heavy metal ions was higher than 85% and Pb2+ concentration in permeation liquid was lower than 0.5 mg/L,which verified that Nanomaterials is effective for the removal of heavy metal ions, and the concentration liquid can be reclaimed.


2009 ◽  
Vol 6 (1) ◽  
pp. 161-168 ◽  
Author(s):  
Tariq S. Najim ◽  
Nazik J. Elais ◽  
Alya A. Dawood

In this study, pine fruit was used as solid adsorbent for removal of ferrous and copper ions from aqueous solutions through batch equilibrium technique. The influence of contact time, pH of the solution and initial concentration of metal ions on adsorbed amount of metal ions were investigated. 90 minutes of adsorption time was found sufficient to reach equilibrium for ferrous ion and 120 minutes for copper ion. Adsorption of metal ions were pH dependent and the results indicate the optimum pH for the removal of Fe+2was found to be 5.0 and that of Cu+2was 7.0, the highest adsorption capacity was found to be 4.8 and 14.1 mg of metal ion per gram of adsorbent at initial concentration of 22.22 mg/L and 57.6 mg/L of ferrous and copper ions respectively and would be higher with higher initial concentration. Ferrous ion was removed by 96.3 - 97.3% and copper ion by 94.1-96% along the whole range of initial concentrations. Isotherm studies showed that the data were best fitted to the Freundlich isotherm model. The kinetic data corresponded well with the pseudo-second order equation, suggesting that the adsorption process is presumably a chemisorption.


2019 ◽  
Author(s):  
Chem Int

A study of removal of heavy metal ions from heavy metal contaminated water using agro-waste was carried out with Musa paradisiaca peels as test adsorbent. The study was carried by adding known quantities of lead (II) ions and cadmium (II) ions each and respectively into specific volume of water and adding specific dose of the test adsorbent into the heavy metal ion solution, and the mixture was agitated for a specific period of time and then the concentration of the metal ion remaining in the solution was determined with Perkin Elmer Atomic absorption spectrophotometer model 2380. The effect of contact time, initial adsorbate concentration, adsorbent dose, pH and temperature were considered. From the effect of contact time results equilibrium concentration was established at 60minutes. The percentage removal of these metal ions studied, were all above 90%. Adsorption and percentage removal of Pb2+ and Cd2+ from their aqueous solutions were affected by change in initial metal ion concentration, adsorbent dose pH and temperature. Adsorption isotherm studies confirmed the adsorption of the metal ions on the test adsorbent with good mathematical fits into Langmuir and Freundlich adsorption isotherms. Regression correlation (R2) values of the isotherm plots are all positive (>0.9), which suggests too, that the adsorption fitted into the isotherms considered.


2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 685
Author(s):  
Ai-Huei Chiou ◽  
Jun-Luo Wei ◽  
Ssu-Han Chen

A novel surface-enhanced Raman scattering (SERS)-based probe to capture heavy metal ion (Zn2+) by bovine serum albumin (BSA) using Si-nanowire (SiNW) arrays with silver nanoparticles (AgNPs) was developed. A layer with AgNPs was deposited on the SiNW surface by RF magnetron sputtering for enhancement of SERS signals. Using a high-resolution transmission electron microscope (HRTEM), the observation reveals that the AgNP layer with depths of 30–75 nm was successfully deposited on SiNW arrays. The Ag peaks in EDS and XRD spectra of SiNW arrays confirmed the presence of Ag particles on SiNW arrays. The WCA observations showed a high affinity of the Ag–SiNW arrays immobilized with BSA (water contact angle (WCA) = 87.1°) and ZnSO4 (WCA = 8.8°). The results of FTIR analysis illustrate that the conjugate bonds exist between zinc sulfate (ZnSO4) and –OH groups/–NH groups of BSA. The resulting SiNWs/Ag NPs composite interfaces showed large Raman scattering enhancement for the capture of heavy metal ions by BSA with a detection of 0.1 μM. BSA and ZnSO4 conjugations, illustrating specific SERS spectra with high sensitivity, which suggests great promise in developing label-free biosensors.


2001 ◽  
Vol 204 (6) ◽  
pp. 1053-1061 ◽  
Author(s):  
A. Sacher ◽  
A. Cohen ◽  
N. Nelson

Transition metals are essential for many metabolic processes, and their homeostasis is crucial for life. Metal-ion transporters play a major role in maintaining the correct concentrations of the various metal ions in living cells. Little is known about the transport mechanism of metal ions by eukaryotic cells. Some insight has been gained from studies of the mammalian transporter DCT1 and the yeast transporter Smf1p by following the uptake of various metal ions and from electrophysiological experiments using Xenopus laevis oocytes injected with RNA copies (c-RNA) of the genes for these transporters. Both transporters catalyze the proton-dependent uptake of divalent cations accompanied by a ‘slippage’ phenomenon of different monovalent cations unique to each transporter. Here, we further characterize the transport activity of DCT1 and Smf1p, their substrate specificity and their transport properties. We observed that Zn(2+) is not transported through the membrane of Xenopus laevis oocytes by either transporter, even though it inhibits the transport of the other metal ions and enables protons to ‘slip’ through the DCT1 transporter. A special construct (Smf1p-s) was made to enhance Smf1p activity in oocytes to enable electrophysiological studies of Smf1p-s-expressing cells. 54Mn(2+) uptake by Smf1p-s was measured at various holding potentials. In the absence of Na(+) and at pH 5.5, metal-ion uptake was not affected by changes in negative holding potentials. Elevating the pH of the medium to 6.5 caused metal-ion uptake to be influenced by the holding potential: ion uptake increased when the potential was lowered. Na(+) inhibited metal-ion uptake in accordance with the elevation of the holding potential. A novel clutch mechanism of ion slippage that operates via continuously variable stoichiometry between the driving-force pathway (H(+)) and the transport pathway (divalent metal ions) is proposed. The possible physiological advantages of proton slippage through DCT1 and of Na(+) slippage through Smf1p are discussed.


2021 ◽  
Author(s):  
Rongrong Si ◽  
Daiqi Wang ◽  
Yehong Chen ◽  
Dongmei Yu ◽  
Qijun Ding ◽  
...  

Abstract Heavy metal ion pollutions are of serious threat for our human health, and advanced technologies on removal of heavy metal ions in water or soil are in the focus of intensive research worldwide. Nanocellulose based adsorbents are emerging as an environmentally friendly appealing materials platform for heavy metal ions removal as nanocellulose has higher specific surface area, excellent mechanical properties and good biocompatibility. In this review, we briefly compare the differences of three kinds of nanocellulose and their preparation method. Then we cover the most recent work on nanocellulose based adsorbents for heavy metal ions removal, and present an in-depth discussion of the modification technologies for nanocellulose in assembling high performance heavy ions adsorbent process. By introducing functional groups, such as amino, carboxyl, phenolic hydroxyl, and thiol, the nanocellulose based adsorbents not only remove single heavy metal ions through ion exchange, chelation/complexation/coordination, electrostatic attraction, hydrophobic actions, binding affinity and redox reactions, but also can selectively adsorb multiple heavy ions in water. Finally, some challenges of nanocellulose based adsorbents for heavy metal ions are also prospected. We anticipate that the review supplies some guides for nanocellulose based adsorbents applied in heavy metal ions removal field.


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