Detection of heavy-metal ions using liquid crystal droplet patterns modulated by interaction between negatively charged carboxylate and heavy-metal cations

Talanta ◽  
2014 ◽  
Vol 128 ◽  
pp. 44-50 ◽  
Author(s):  
Gyeo-Re Han ◽  
Chang-Hyun Jang
Keyword(s):  
Heavy Metal ◽  
Liquid Crystal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Metal Cations ◽  
Heavy Metal Cations ◽  
Liquid Crystal Droplet

scholarly journals Determination of heavy metal ions in extracts of the prickly root of eleutherococcus

2019 ◽  
Vol 57 (1) ◽  
pp. 66-71
Author(s):  
Alsu S. Ibragimova ◽  
◽  
Alla Yu Krynitskaya ◽  
Elena V. Petukhova ◽  
Pavel P. Sukhanov ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Tap Water ◽  
Metal Cations ◽  
Aqueous Extracts ◽  
Plant Materials ◽  
Heavy Metal Cations ◽  
Pollution Indicator ◽  
The City

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.

Comparison of surface functional groups and metal uptake efficiency of rice husk harvested from different climatic zones

2012 ◽  
Vol 65 (10) ◽  
pp. 1738-1744 ◽  
Author(s):  
Amir Hossein Matin ◽  
Shokooh Sadat Khaloo ◽  
Abbas Akbarzadeh ◽  
Mohammad Riahi
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Functional Groups ◽  
Rice Husk ◽  
Heavy Metal Ions ◽  
Metal Cations ◽  
Climatic Conditions ◽  
Water Solutions ◽  
Heavy Metal Cations ◽  
Climatic Regions

Rice husk (RH) is a very effective natural adsorbent for fast removal of heavy metal cations from water solutions. Application of RH for removal of some heavy metal ions, such as Ni, Zn, Mn, Co, Cu, Pb and Cd from water solutions has been studied and different maximum adsorption capacities and a variety of optimized conditions were reported in the literature. In this work, the efficiency of RH harvested from different climatic regions was studied. For this proposal, different RH samples were collected from three different climatic regions of Iran (nominated as RH1 to RH3); their removal efficiencies of heavy metal cations of Ni2+, Cu2+ and Cd2+ were investigated and compared. The adsorption data at optimum conditions could be assessed well by both Langmuir and Freundlich models. Statistical analysis of the results of adsorption isotherms showed that different RH samples have different efficiencies in uptake of these heavy metal ions. The RH samples were characterized using Fourier transform infrared spectroscopy and Boehm titration, which indicated that amounts of functional groups differed between RHs that are grown in different climatic conditions.

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
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Kinetics ◽  
Contact Time ◽  
Adsorption Process ◽  
Metal Cations ◽  
Kinetics Model ◽  
Batch Method ◽  
Heavy Metal Cations ◽  
Kinetics Of

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).

scholarly journals Bovine Serum Albumin Protein-Based Liquid Crystal Biosensors for Optical Detection of Toxic Heavy Metals in Water

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 298 ◽  
Author(s):  
Noor ul Amin ◽  
Humaira Masood Siddiqi ◽  
Yang Kun Lin ◽  
Zakir Hussain ◽  
Nasir Majeed
Keyword(s):  
Heavy Metal ◽  
Liquid Crystal ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Metal Ions ◽  
Bovine Serum ◽  
Heavy Metal Ions ◽  
Limit Of Detection ◽  
Optical Image ◽  
Toxic Heavy Metals

A new methodology involving the use of Bovine Serum Albumin (BSA) as a probe and liquid crystal (LC) as a signal reporter for the detection of heavy metal ions in water at neutral pH was developed. BSA acted as a multi-dentate ligand for the detection of multiple metal ions. The LC sensor was fabricated by immobilizing 3 µg mL−1 BSA solution on dimethyloctadecyl-[3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP)-coated glass slides. In the absence of heavy metal ions, a dark optical image was observed, while in their presence, a dark optical image turned to bright. The optical response was characterized by using a polarized optical microscope (POM). The BSA based LC sensor selectively detected toxic metal ions as compared to s block metal ions and ammonium ions in water. Moreover, the limit of detection was found to be very low (i.e., 1 nM) for the developed new biosensor in comparison to reported biosensors.

Regularities and mechanism of heavy metal cations sorption and (or) proton desorption by chitosan from aqueous solutions

2019 ◽  
Vol 97 (8) ◽  
pp. 621-628 ◽  
Author(s):  
T.E. Nikiforova ◽  
V.A. Kozlov ◽  
M.K. Islyaikin
Keyword(s):  
Heavy Metal ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Metal Cations ◽  
Batch Adsorption ◽  
Amino Groups ◽  
Acidic Media ◽  
Chitosan Beads

The sorption process of heavy metal ions from aqueous solutions using chitosan flakes and chitosan beads was studied. Chitosan gel beads were prepared using covalent crosslinking of chitosan chains by epichlorohydrin with ionic gelation by sodium tripolyphosphate. The capability of chitosan beads to absorb the heavy metal ions from aqueous solutions was studied, and the physicochemical characteristics of the sorbent were evaluated using SEM and FTIR on the model solution treatment. It was found that competitive proton sorption takes place in acidic media, which results in a transformation of amino groups into inactive ammonium-salt form and decreases in heavy metal sorption onto chitosan from aqueous acidic media. Batch adsorption experiments were performed to examine the influence of various factors such as the initial concentration of metal salts, pH, and agitation duration on the process. It was established that metal ion sorption is pH dependent and has an optimum effect at a pH of 6.0. Following the Langmuir equation, the maximum sorption of Cu2+ions is estimated to be 1,6 mol/kg of modified chitosan. The kinetic study revealed that the adsorption kinetics are well-fitted to the kinetic equation of pseudo second order. Thus, sorption of heavy metal ions by chitosan is considered to be a competitive process that occurs on amino groups of the sorbent with equivalent coordinated participation of metal cations, protons, and anions.

scholarly journals Sorption of Fulvic Acids and Their Compounds with Heavy Metal Ions on Clay Minerals

Soil Systems ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Maria Nikishina ◽  
Leonid Perelomov ◽  
Yury Atroshchenko ◽  
Evgenia Ivanova ◽  
Loik Mukhtorov ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Clay Minerals ◽  
Heavy Metal Ions ◽  
Metal Cations ◽  
Fulvic Acids ◽  
Mineral Surfaces ◽  
Equilibrium Solutions ◽  
Complex Processes ◽  
Component Systems

In real soils the interaction of humic substances with clay minerals often occurs with the participation of metal cations. The adsorption of fulvic acids (FA) solution and their solutions in the presence of heavy metal ions (Pb or Zn) on two clay minerals (kaolinite and bentonite) was investigated by measurement of the optical density changes in the of equilibrium solutions. The FA adsorption by bentonite at the concentrations 0.05–1 g/L proceeds according to the polymolecular mechanism and has a stepwise character. The adsorption of FA on kaolinite can be described by the mechanism of monomolecular adsorption. In three-component systems, including FA, trace element ions and a clay mineral, complex processes occur, including the formation of complexes and salts and their adsorption. The sorption of colored complexes of FA with Pb on the surface of kaolinite and bentonite increases with increasing metal concentrations (0.5–2 mmol/L). The interaction of the FA-Zn2+ compounds with bentonite is a more complicated process—adsorption takes place at the lowest concentration used only. Thus, binding of FA by clay minerals in the presence of metal cations is a complex phenomenon due to the chemical heterogeneity of FA, different properties of metals, characteristics of mineral surfaces and the variability of environmental conditions.

Are engineered nanomaterials superior adsorbents for removal and pre-concentration of heavy metal cations from water?

RSC Advances ◽  
2014 ◽  
Vol 4 (86) ◽  
pp. 46122-46125 ◽  
Author(s):  
Kun Yang ◽  
Wei Wei ◽  
Long Qi ◽  
WenHao Wu ◽  
QingFeng Jing ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Metal Cations ◽  
Engineered Nanomaterials ◽  
Heavy Metal Cations ◽  
Removal Of Metal ◽  
Removal Of Metal Ions

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.

scholarly journals The Utilization of Poly-37,40-diallyl-38,39,41,42,-tetrahydroxycalix[6]arenes Compound as Adsorbent for Heavy Metal Cations Cd(II), Cr(III) and Cu(II)

2020 ◽  
Vol 5 (2) ◽  
pp. 94
Author(s):  
Susy Yunita Prabawati ◽  
Jumina Jumina ◽  
Sri Juari Santosa ◽  
Mustofa Mustofa
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Kinetics ◽  
Contact Time ◽  
Metal Ion ◽  
Adsorption Process ◽  
Metal Cations ◽  
Batch Method ◽  
Heavy Metal Cations ◽  
Adsorption Capacities

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.  

scholarly journals Cell selection with heavy metal ions for obtaining wheat and maize forms tolerant to osmotic stresses

2018 ◽  
Vol 22 ◽  
pp. 318-322
Author(s):  
L. E. Sergeeva ◽  
L. I. Bronnikova
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Cell Lines ◽  
Heavy Metal Ions ◽  
Cell Selection ◽  
Plant Tolerance ◽  
New Approach ◽  
Heavy Metal Cations ◽  
Modified Media ◽  
Initial Selection

Aim. The obtaining tolerant to salt and water stresses wheat and maize variants via cell selection with barium and cadmium heavy metal cations were the idea. Barium cations disrupt the cell potassium transport. Cadmium cations affect the dehydrins. The maintenance of these parameters under stress conditions provides the plant tolerance. Methods. Modified media for initial selection were developed by the supplement of the lethal doses of heavy metal ions. Wheat and maize suspension cultures were plated on selective media. The relative fresh biomass growth was the marker of variant stress tolerance. Results. Ba-resistant and Cd‑resistant plant cell lines were obtained. Those variants were tested under salinity and water stress pressure at lethal for wild type cells doses. Cell lines demonstrated the combined tolerance to abiotic stresses. Conclusions. The cell selection with heavy metal ions – is a new approach for isolation cell variants with higher levels of osmotic stresses tolerance. Keywords: cereals, osmotic stresses, cell selection with heavy metal ions, combined tolerance.

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