scholarly journals Silicon Binding in Soil Humic Substances

2021 ◽  
Author(s):  
sanjib kar
Keyword(s):  
Humic Acid ◽  
Metal Ions ◽  
Analytical Data ◽  
Xrd Analysis ◽  
Exchange Capacity ◽  
Acid Molecule ◽  
Molecular Weights ◽  
Dta Analysis ◽  
Metallic Compounds ◽  
Removal Of Metal Ions

Abstract In the present study, an attempt has been made to probe the nature of silicon-humus bonding as it occurs in nature ('untreated') as compared to the samples wherefrom the metalloid ions have been removed ('treated'). Infrared (IR) spectroscopy revealed the role of carboxylic acid groups of Humic acid (HA) in metal complexation. Si-O absorption reduced considerably in treatment to remove metalloid ions, but it remained quite strong in the treated samples indicating a strong Si-O linkage with humus. In XRD analysis, treated samples showed stronger γ-bands. DTA analysis indicated structural strain on the humic molecule induced by complexation with metalloid ions. Treated HAs had higher acidity values compared to the untreated samples. Treatment for removal of metal ions caused an increase in cation exchange capacity while a reduction of E4/E6 ratio. Treated HAs also showed higher molecular weights (Mv) compared to the untreated samples. Removal of metals renders certain groups free which form intermolecular bonds. On the basis of analytical data, it was observed that there is still some silicon bonds within humic acid molecule, even after removal of silicon by forcing conditions. Association of silicon with humus in soils are quantitatively and qualitatively different from other metal ions and it is clear that humic acid molecule possess silicon-humus bond like pure organo-metallic compounds.

scholarly journals Silicon Binding in Soil Humic Substances

2021 ◽  
Author(s):  
sanjib kar
Keyword(s):  
Humic Acid ◽  
Metal Ions ◽  
Analytical Data ◽  
Xrd Analysis ◽  
Exchange Capacity ◽  
Acid Molecule ◽  
Molecular Weights ◽  
Dta Analysis ◽  
Metallic Compounds ◽  
Removal Of Metal Ions

Abstract In the present study, an attempt has been made to probe the nature of silicon-humus bonding as it occurs in nature ('untreated') as compared to the samples wherefrom the metalloid ions have been removed ('treated'). Infrared (IR) spectroscopy revealed the role of carboxylic acid groups of Humic acid (HA) in metal complexation. Si-O absorption reduced considerably in treatment to remove metalloid ions, but it remained quite strong in the treated samples indicating a strong Si-O linkage with humus. In XRD analysis, treated samples showed stronger γ-bands. DTA analysis indicated structural strain on the humic molecule induced by complexation with metalloid ions. Treated HAs had higher acidity values compared to the untreated samples. Treatment for removal of metal ions caused an increase in cation exchange capacity while a reduction of E4/E6 ratio. Treated HAs also showed higher molecular weights (Mv) compared to the untreated samples. Removal of metals renders certain groups free which form intermolecular bonds. On the basis of analytical data, it was observed that there is still some silicon bonds within humic acid molecule, even after removal of silicon by forcing conditions. Association of silicon with humus in soils are quantitatively and qualitatively different from other metal ions and it is clear that humic acid molecule possess silicon-humus bond like pure organo-metallic compounds.

Zinc and cadmium mobility in sand: effects of pH, speciation, Cation Exchange Capacity (CEC), humic acid and metal ions

Chemosphere ◽  
1998 ◽  
Vol 36 (10) ◽  
pp. 2283-2290 ◽  
Author(s):  
P. Warwick ◽  
A. Hall ◽  
V. Pashley ◽  
J. Van der Lee ◽  
A. Maes
Keyword(s):  
Humic Acid ◽  
Metal Ions ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Effects Of Ph

scholarly journals Electrical Conductivity and Ion Exchange Properties of Polyaniline Antimony Tin Tung state Nano composite

2021 ◽  
Vol 37 (2) ◽  
pp. 388-396
Author(s):  
Preethab B
Keyword(s):  
Ion Exchange ◽  
Metal Ions ◽  
Xrd Analysis ◽  
Distribution Coefficients ◽  
Exchange Capacity ◽  
Polluted Water ◽  
Ion Exchange Capacity ◽  
Nano Composite ◽  
Exchange Character ◽  
Differential Selectivity

The nano composite, polyaniline antimony tin tungstate in the H+ form was synthesized by a simple general method. EDS and ICP- AES methods were used to find the chemical constitution of the material. Further characterizations were done by TGA, XRD analysis, FTIR Spectroscopic analysis, UV-Visible DRS studies to find the optical properties, SEM for finding surface morphology, etc. Size determination using XRD peaks and TEM images confirmed its nano size. Investigation on ion exchange capacity and distribution coefficients for many metal ions revealed the ion exchange character. The composite exhibited differential selectivity forheavy metal ions such as PbII, ThIV, HgIV, etc. which are important in environmental applications like separation and treatment of polluted water from these metal ions. The electrical properties studied by Four–probe method revealed a high conductivity of 0.42 S/cm at room temperature and it decreases with an increase in temperature. These results suggest various applications of this nano compositein optoelectronics.

Comparison of the fixation of several metal ions onto a low-cost biopolymer

2002 ◽  
Vol 2 (5-6) ◽  
pp. 217-224 ◽  
Author(s):  
Z. Reddad ◽  
C. Gérente ◽  
Y. Andrès ◽  
P. Le Cloirec
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Low Cost ◽  
Operating Conditions ◽  
Order Kinetic ◽  
Adsorption Mechanisms ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Beet Pulp ◽  
Removal Of Metal Ions

In the present work, sugar beet pulp, a common waste from the sugar refining industry, was studied in the removal of metal ions from aqueous solutions. The ability of this cheap biopolymer to sorb several metals namely Pb2+, Cu2+, Zn2+, Cd2+ and Ni2+ in aqueous solutions was investigated. The metal fixation capacities of the sorbent were determined according to operating conditions and the fixation mechanisms were identified. The biopolymer has shown high elimination rates and interesting metal fixation capacities. A pseudo-second-order kinetic model was tested to investigate the adsorption mechanisms. The kinetic parameters of the model were calculated and discussed. For 8 × 10-4 M initial metal concentration, the initial sorption rates (v0) ranged from 0.063 mmol.g-1.min-1 for Pb2+ to 0.275 mmol.g-1.min-1 for Ni2+ ions, with the order: Ni2+ > Cd2+ > Zn2+ > Cu2+ > Pb2+. The equilibrium data fitted well with the Langmuir model and showed the following affinity order of the material: Pb2+ > Cu2+ > Zn2+ > Cd2+ > Ni2+. Then, the kinetic and equilibrium parameters calculated qm and v0 were tentatively correlated to the properties of the metals. Finally, equilibrium experiments in multimetallic systems were performed to study the competition of the fixation of Pb2+, Zn2+ and Ni2+ cations. In all cases, the metal fixation onto the biopolymer was found to be favourable in multicomponent systems. Based on these results, it is demonstrated that this biosorbent represents a low-cost solution for the treatment of metal-polluted wastewaters.

Utilization of Polysaccharides and their Derivatives in the Removal of Metal Ions: Role and Recent Advancement

2020 ◽  
Vol 13 ◽  
Author(s):  
Rishabha Malviya ◽  
Pramod Sharma ◽  
Akanksha Sharma
Keyword(s):  
Waste Water ◽  
Heavy Metal ◽  
Metal Ions ◽  
Industrial Waste ◽  
Heavy Metal Ions ◽  
Environmental Hazards ◽  
Industrial Waste Water ◽  
Recent Advancement ◽  
Removal Of Metal ◽  
Removal Of Metal Ions

: Manuscript discussed about the role of polysaccharides and their derivatives in the removal of metal ions from industrial waste water. Quick modernization and industrialization increases the amount of various heavy metal ions in the environment. They can possess various disease in humans and also causes drastic environmental hazards. In this review the recent advancement for the adsorption of heavy metal ions from waste water by using different methods has been studied. Various natural polymers and their derivatives are act as effective adsorbents for the removal of heavy metal ions from the waste water released from the industries and the treated water released into the environment can decreases the chances of diseases in humans and environmental hazards. From the literature surveys it was concluded that the removal of heavy metal ions from the industrial waste water was important to decrease the environmental pollution and also diseases caused by the heavy metal ions. Graft copolymers were acts as most efficient adsorbent for the removal of heavy metal ions and most of these followed the pseudo first order and pseudo second order model of kinetics.

The effect of partial exchange of sulphonated macroporous styrene-divinylbenzene copolymers for different ions on their catalytic activity

1981 ◽  
Vol 46 (10) ◽  
pp. 2354-2363 ◽  
Author(s):  
Svatomír Kmošták ◽  
Karel Setínek
Keyword(s):  
Catalytic Activity ◽  
Transition Metal ◽  
Metal Ions ◽  
Gas Phase ◽  
Transition Metal Ions ◽  
Exchange Capacity ◽  
Total Exchange Capacity ◽  
Styrene Divinylbenzene ◽  
Na Ions ◽  
Type Of Transition

The catalytic activity of sulphonated macroporous styrene-divinylbenzene copolymers, the exchange capacity of which was neutralized from 30, 50 and 80% by Fe(III) ions and from 30% by Na ions and that of Wofatit Y-37 ion exchanger neutralized from 10% of its total exchange capacity by several transition metal ions and by sodium has been studied in isomerisation of cyclohexene and dehydration of 1-propanol in the gas phase at 130 °C. It was demonstrated that in both reactions transition metal ions exhibit additional effect to the expected neutralization of the polymer acid groups. In the case of cyclohexene isomerization, this effect depends on the degree of crosslinking of polymer mass of the catalyst. Such dependence has not been, however, observed in dehydration of 1-propanol. The type of transition metal ions did not exhibit any significant effect on the catalytic activity of the polymer catalysts studied.

scholarly journals Purification and characterization of fat body lipase from the greater wax moth, Galleria mellonella (Lepidoptera: Pyralidae)

2019 ◽  
Vol 81 (1) ◽  
Author(s):  
Rahma R. Z. Mahdy ◽  
Shaimaa A. Mo’men ◽  
Marah M. Abd El-Bar ◽  
Emad M. S. Barakat
Keyword(s):  
Metal Ions ◽  
Kinetic Parameters ◽  
Biochemical Characterization ◽  
Galleria Mellonella ◽  
Fat Body ◽  
Specific Activity ◽  
Larval Instar ◽  
Gel Filtration ◽  
Molecular Weights

Abstract Background Insect lipid mobilization and transport are currently under research, especially lipases and lipophorin because of their roles in the production of energy and lipid transport at a flying activity. The present study has been conducted to purify intracellular fat body lipase for the first time, from the last larval instar of Galleria mellonella. Results Purification methods by combination of ammonium sulfate [(NH4)2SO4] precipitation and gel filtration using Sephadex G-100 demonstrated that the amount of protein and the specific activity of fat body lipase were 0.008633 ± 0.000551 mg/ml and 1.5754 ± 0.1042 μmol/min/mg protein, respectively, with a 98.9 fold purity and recovery of 50.81%. Hence, the sephadex G-100 step was more effective in the purification process. SDS-PAGE and zymogram revealed that fat body lipase showed two monomers with molecular weights of 178.8 and 62.6 kDa. Furthermore, biochemical characterization of fat body lipase was carried out through testing its activities against several factors, such as different temperatures, pH ranges, metal ions, and inhibitors ending by determination of their kinetic parameters with the use of p-nitrophenyl butyrate (PNPB) as a substrate. The highest activities of enzyme were determined at the temperature ranges of 35–37 °C and 37–40 °C and pH ranges of 7–9 and 7–10. The partially purified enzyme showed significant stimulation by Ca2+, K+, and Na+ metal ions indicating that fat body lipase is metalloproteinase. Lipase activity was strongly inhibited by some inhibitors; phenylmethylsulfonyl fluoride (PMSF), ethylene-diaminetetractic acid (EDTA), and ethylene glycoltetraacetic acid (EGTA) providing evidence of the presence of serine residue and activation of enzymes by metal ions. Kinetic parameters were 0.316 Umg− 1 Vmax and 301.95 mM Km. Conclusion Considering the purification of fat body lipase from larvae and the usage of some inhibitors especially ion chelating agents, it is suggested to develop a successful control of Galleria mellonella in near future by using lipase inhibitors.

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