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.

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.

Clay mineral formation under lateritic weathering conditions

Clay Minerals ◽  
1977 ◽  
Vol 12 (4) ◽  
pp. 281-288 ◽  
Author(s):  
Hermann Harder
Keyword(s):  
Solid Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Clay Minerals ◽  
Amorphous Silica ◽  
Heavy Metal Ions ◽  
Weathering Crust ◽  
Mineral Formation ◽  
Serpentine Minerals ◽  
Weathering Zone

AbstractAmorphous hydroxides of Al, Fe, Mn, Mg, Zn, Co, Ni, etc., are capable of coprecipitating SiO2 even from very dilute (weathering) solutions. Silica minerals form only in those precipitates from solutions undersaturated with respect to amorphous silica (100 ppm SiO2 at 20°C). With higher SiO2 concentrations the precipitates remain amorphous. The size of the cations should allow 6-fold coordination and giving a brucite-like layer. Most suitably sized octahedral ions are Mg, Zn, Ni, Co and Fe2+ (size 0·78–0·82 Å), and chemically pure three- and two-layer clay minerals with these ions are easily synthesized. With a relatively high content of silica in solution (60 ppm SiO2 with 1–2·5 ppm metal) several smectite minerals could be synthesized. With a low content of silica in solution (5–20 ppm SiO2 and ca. 2 ppm metal) the serpentine minerals, could be synthesized.It is possible to crystallize the difficult to form Al-clay minerals in a solid solution with these more easily synthesized clay minerals.Clay minerals with the heavy metal ions of Ni, Co, Zn, and with Cu, Cr, etc., can be found in the weathering zone of Gossan and in the lateritic weathering crust of ultrabasic rocks.

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.

Film-Pore-[Concentration-Dependent] Surface Diffusion model for heavy metal ions adsorption: Single and multi-component systems

2017 ◽  
Vol 107 ◽  
pp. 486-497 ◽  
Author(s):  
Mohammad Kavand ◽  
Neda Asasian ◽  
Mansooreh Soleimani ◽  
Tahereh Kaghazchi ◽  
Raoof Bardestani
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Surface Diffusion ◽  
Diffusion Model ◽  
Heavy Metal Ions ◽  
Component Systems

Anomalous Small-Angle X-ray Scattering Studies of Interlayer Heavy Metal Ions in Clay Minerals

1998 ◽  
Vol 10 (4) ◽  
pp. 1130-1134 ◽  
Author(s):  
Kathleen A. Carrado ◽  
P. Thiyagarajan ◽  
Kang Song ◽  
Randall E. Winans
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Clay Minerals ◽  
Small Angle ◽  
Heavy Metal Ions ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

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.

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