scholarly journals Molecularly Imprinted Polymers for Removal of Metal Ions: An Alternative Treatment Method

Biomimetics ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 38 ◽  
Author(s):  
Özgecan Erdem ◽  
Yeşeren Saylan ◽  
Müge Andaç ◽  
Adil Denizli

Aquatic and terrestrial environment and human health have been seriously threatened with the release of metal-containing wastewater by the rapid growth in the industry. There are various methods which have been used for removal of ions from the environment, such as membrane filtration, ion exchange, membrane assisted liquid extraction and adsorption. As a sort of special innovation, a polymerization technique, namely molecular imprinting is carried out by specific identification for the target by mixing it with a functional monomer. After the polymerization occurred, the target ion can be removed with suitable methods. At the end of this process, specific cavities, namely binding sites, are able to recognize target ions selectively. However, the selectivity of the molecularly imprinted polymer is variable not only because of the type of ligand but also charge, size coordination number, and geometry of the target ion. In this review, metal ion-imprinted polymeric materials that can be applied for metal ion removal from different sources are discussed and exemplified briefly with different metal ions.

2021 ◽  
Vol 25 (9) ◽  
pp. 127-132
Author(s):  
Anamica . ◽  
P.P. Pande

The crosslinkers allyl mannitol (AM), allyl sorbitol (AS) and allyl pentaerythritol (AP) have been used for the synthesis of crosslinked polymeric gels of acrylic acid. These gels were used for the removal of heavy metal ions from water. The quantitative removal of metal ions was determined with the support of UV-visible absorption spectroscopy. The results show that the fully dried hydrogel samples have better adsorption potential for heavy metal ion removal. The kinetics of metal ion adsorption during the treatment of wastewater has also been studied. It was found that under certain conditions, the kinetics involved may be of pseudo first order while under different set of conditions, the kinetics involved is of pseudo second order.


2006 ◽  
Vol 05 (3) ◽  
pp. 21-30
Author(s):  
Denise Alves FUNGARO ◽  
Juliana de Carvalho IZIDORO

The capacity of synthesized zeolites from Brazilian coal ash for the removal of metal ions from aqueous solutions has been investigated. Equilibrium data obtained have been found to fit both the Langmuir and Freundlich adsorption isotherms. The zeolitic material prepared with coal ash from baghouse filter showed the highest removal efficiencies. The metal ion selectivity of this product was determined as: Pb2+ > Cd2+ > Cu2+ > Zn2+ > Ni2+. The maximum cation exchange capacities were between 32.9 and 246.9 mg g-1. Tests showed that the zeolitic material was suitable for removal of zinc from electroplating effluent.


Author(s):  
Andre Baldermann ◽  
Andrea Cäcilia Grießbacher ◽  
Claudia Baldermann ◽  
Bettina Purgstaller ◽  
Ilse Letofsky-Papst ◽  
...  

The capacity and the mechanism of the adsorption of aqueous barium (Ba), cobalt (Co), strontium (Sr) and zinc (Zn) by Ecuadorian (NatAllo) and synthetic (SynAllo-1 and SynAllo-2) allophanes were studied as a function of contact time, pH and metal ion concentration using kinetic and equilibrium experiments. The mineralogy, nano-structure and chemical composition of the allophanes were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and specific surface area analyses. The evolution of adsorption fitted to a pseudo-first-order reaction kinetics, where equilibrium between aqueous metal ions and allophane was reached within < 10 min. The metal ion removal efficiencies varied from 0.7 to 99.7 % at pH 4.0 to 8.5. At equilibrium, the adsorption behavior is better described by the Langmuir model than by the Dubinin-Radushkevich model, yielding sorption capacities of 10.6, 17.2 and 38.6 mg/g for Ba^(2+), 12.4, 19.3 and 29.0 mg/g for HCoO_2^-, 7.2, 15.9 and 34.4 mg/g for Sr^(2+) and 20.9, 26.9 and 36.9 mg/g for Zn^(2+), respectively, by NatAllo, SynAllo-2 and SynAllo-1. The uptake mechanism is based on a physical adsorption process. Allophane holds great potential to remove aqueous metal ions and could be used instead of zeolites, montmorillonite, carbonates and phosphates for wastewater treatment.


Author(s):  
I. O. Ekwere ◽  
M. Horsfall ◽  
J. O. E. Otaigbe

The photocatalytic reduction of Cu (II), Pb (II), Cd (II) and Cr (VI) ions in aqueous solution has been investigated. The photocatalyst utilized was nano titanium dioxide, composed of 80% anatase and 20% rutile; the UV light source was a 15 W UV bulb with a wavelength of 254 nm. The results obtained indicated a reduction efficiency order as follows; Cr6+ > Cu2+ > Pb2+ > Cd2+. It was observed that these results correlate with the respective reduction potentials of the metal ions. The effect of pH on the photocatalytic reduction of the metal ions was also carried out and results obtained indicated that with the exception of Cr (VI) ions, higher percentage removal of metal ions from their aqueous solution was recorded at alkaline pH than at acidic pH. This was attributed to an extensive formation of precipitate by the metal ions at alkaline pH. Kinetic studies revealed that the removal of metal ions from their solutions largely followed the pseudo- first-order kinetics. Therefore, the results of this study will be useful in metal ion removal from industrial waste water using photocatalytic process.


RSC Advances ◽  
2021 ◽  
Vol 11 (58) ◽  
pp. 36528-36553
Author(s):  
Ahmad K. Badawi ◽  
M. Abd Elkodous ◽  
Gomaa A. M. Ali

Various materials including waste precursors used as adsorbents for water treatment (dyes and metal ions removal).


2020 ◽  
Vol 17 (1) ◽  
pp. 74-90 ◽  
Author(s):  
Nader Ghaffari Khaligh ◽  
Mohd Rafie Johan

: A variety of processes were reported for efficient removing of heavy metal from wastewater, including but not limited to ion exchange, reverse osmosis, membrane filtration, flotation, coagulation, chemical precipitation, solvent extraction, electrochemical treatments, evaporation, oxidation, adsorption, and biosorption. Among the aforementioned techniques, adsorption/ion exchange has been known as a most important method for removing heavy metal ions and organic pollutants due to great removal performance, simple and easy process, cost-effectiveness and the considerable choice of adsorbent materials. : Nanotechnology and its applications have been developed in most branches of science and technology. Extensive studies have been conducted to remove heavy metal ions from wastewater by preparation and applications of various nanomaterials. Nanomaterials offer advantages in comparison to other materials including an extremely high specific surface area, low-temperature modification, short intraparticle diffusion distance, numerous associated sorption sites, tunable surface chemistry, and pore size. In order to evaluate an adsorbent, two key parameters are: the adsorption capacity and the desorption property. The adsorption parameters including the absorbent loading, pH and temperature, concentration of heavy metal ion, ionic strength, and competition among metal ions are often studied and optimized. : Several reviews have been published on the application of Graphene (G), Graphene Oxide (GO) in water treatment. In this minireview, we attempted to summarize the recent research advances in water treatment and remediation process by graphene-based materials and provide intensive knowledge of the removal of pollutants in batch and flow systems. Finally, future applicability perspectives are offered to encourage more interesting developments in this promising field. This minireview does not include patent literature.


2021 ◽  
pp. 0958305X2198988
Author(s):  
Adeyinka Sikiru Yusuff

Aluminium oxide modified onion skin waste (Al2O3/OSW) was characterized and used for adsorption of metal ions (Pb2+ and Cd2+) in this study, and the relations between sorbent properties and metal ion sorption were investigated. The effects of adsorption process conditions on metal ion removal efficiency, including initial cation concentration, contact time, adsorbent dosage and pH, were examined. The obtained adsorption data were analyzed by various adsorption isotherm and kinetic models. It was found that the optimum values of the initial concentration, contact time, adsorbent dosage and pH were 10 mg/L, 120 min, 1.6 g/L and 6.0, respectively. At these optimum conditions, maximum removal percentages of Pb2+ and Cd2+ were 91.23 and 94.10%, respectively. The isotherm and kinetic studies showed a multilayer adsorbate-adsorbent system with the dominance of the chemisorption mechanism. The study concluded that onion skin waste is a viable, cheap and effective alternative for removing heavy metal ions from water/wastewater.


2014 ◽  
Vol 1675 ◽  
pp. 209-214
Author(s):  
Adnan Mujahid ◽  
Faisal Amin ◽  
Tajamal Hussain ◽  
Naseer Iqbal ◽  
Asma Tufail Shah ◽  
...  

ABSTRACTImprinting is a well-established technique to induce recognition features in both organic and inorganic materials for a variety of target analytes. In this study, ion imprinted polysiloxanes with varying percentage of coupling agent i.e. 3-chloro propyl trimethoxy silane (CPTM) were synthesized by sol-gel method for imprinting of Cr3+. The imprinting of Cr3+ in cross-linked siloxane network was investigated by FT-IR which indicates the metal ion is coordinated with oxygen atoms of polysiloxanes. SEM images revealed that imprinted polysiloxanes possess uniform particles of submicron size. It was experienced that by increasing the concentration of CPTM up to 10% (v/v) substantially improves the binding capacity of polysiloxanes which allows us to recognized Cr3+ down to 50µg/L. Furthermore, the selectivity of Cr3+-imprinted polysiloxanes was evaluated by treating them with other competing metal ions of same concentration i.e. Cr6+, Pb2+ and Ni2+. In this regard, polysiloxanes showed much higher binding for imprint ion i.e. Cr3+ in comparison to above mentioned metal ions. Finally, the regenerated polysiloxanes were studied in order to reuse them thus, developing cost effective biomimetic sensor coatings.


2018 ◽  
Vol 18 (3) ◽  
pp. 472
Author(s):  
Venty Suryanti ◽  
Sri Hastuti ◽  
Tutik Dwi Wahyuningsih ◽  
Mudasir Mudasir ◽  
Dian Kresnadipayana ◽  
...  

The batch removal of Cu(II), Cd(II) and Pb(II) from individual heavy metal ion aqueous synthetic solution using biosurfactants produced by Pseudomonas aeruginosa with corn oil as substrate was investigated. The metal ion removal process of crude preparation biosurfactants (CPB) was established to be dependent on the initial pH and contact time. The optimum metal removal was observed at pH 6.0 of the initial metal solution and 10 min of contact time. The affinity sequence for metal ion removal was Pb(II)>Cd(II)>Cu(II). The removal capacity value of biosurfactant for Cu(II), Cd(II) and Pb(II) from single metal ions solution were 0.169, 0.276 and 0.323 mg/g, respectively. The removal capacity value of biosurfactant for Cu(II), Cd(II) and Pb(II) from multi metal ions solution were 0.064, 0.215 and 0.275 mg/g, respectively. The removal capacity of individual metal ion was diminished by the presence of other metal ions in multi metal ions from synthetic aqueous solution. The removal capacity value of biosurfactant for Cu(II), Cd(II) and Pb(II) from silver industry wastewater were 0.027, 0.055 and 0.291 mg/g, respectively. The results indicated that biosurfactants have potential to be used in the remediation of heavy metals in industrial wastewater.


Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2325 ◽  
Author(s):  
Mubeen Isam ◽  
Lavania Baloo ◽  
Shamsul Rahman Mohamed Kutty ◽  
Saba Yavari

The removal of Pb (II) and Cu (II) ions by using marine red macroalgae (Gracilaria changii) as a biosorbent material was evaluated through the batch equilibrium technique. The effect of solution pH on the removal of metal ions was investigated within the range of 2–7. The response surface methodology (RSM) technique involving central composite design (CCD) was utilised to optimise the three main sorption parameters, namely initial metal ion concentration, contact time, and biosorbent dosage, to achieve maximum ion removal. The models’ adequacy of response was verified by ANOVA. The optimum conditions for removal of Pb (II) and Cu (II) were as follows: pH values of 4.5 and 5, initial concentrations of 40 mg/L, contact times of 115 and 45 min, and biosorbent dosage of 1 g/L, at which the maximum removal percentages were 96.3% and 44.77%, respectively. The results of the adsorption isotherm study showed that the data fitted well with the Langmuir’s model for Pb (II) and Cu (II). The results of the adsorption kinetic study showed that the data fitted well with the pseudo-second order model for Pb (II) and Cu (II). In conclusion, red alga biomass exhibits great potential as an efficient low-cost sorbent for removal of metal ions.


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