scholarly journals Evaluation of Adsorption Mechanism of Chromium(VI) Ion Using Ni-Al Type and Ni-Al-Zr Type Hydroxides

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 551
Author(s):  
Fumihiko Ogata ◽  
Noriaki Nagai ◽  
Ayako Tabuchi ◽  
Megumu Toda ◽  
Masashi Otani ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Sodium Hydroxide Solution ◽  
Aqueous Media ◽  
Elemental Distribution ◽  
Nickel Aluminum ◽  
Experimental Conditions ◽  
Molar Ratios ◽  
Chromium Vi ◽  
Effects Of Ph ◽  
Aluminum Base

To evaluate the feasibility of nickel–aluminum (the Ni2+:Al3+ molar ratios of 1.0:1.0 and 1.0:2.0 are denoted as NA11 and NA12, respectively) and nickel–aluminum–zirconium type (the Ni2+:Al3+:Zr4+ molar ratios of 0.9:1.0:0.09 and 0.9:2.0:0.09 are denoted as NAZ1 and NAZ2, respectively) hydroxides for Cr(VI) removal from aqueous media, the adsorption capability and adsorption mechanism of Cr(VI) using the above-mentioned adsorbents were investigated in this study. The quantity of Cr(VI) adsorbed onto NA11, NA12, NAZ1, and NAZ2 was 25.5, 25.6, 24.1, and 24.6 mg g−1, respectively. However, the quantity of aluminum (base metal) released from NA11 (approximately 0.14 mg g−1) was higher than that from NAZ1 (approximately 1.0 µg g−1), indicating that NAZ1 was more suitable for Cr(VI) removal than NA11. In addition, the effects of pH, contact time, and temperature on the adsorption of Cr(VI) were evaluated. Moreover, to elucidate the adsorption mechanism of Cr(VI) using NA11 and NAZ1, the elemental distribution, X-ray photoelectron spectrometry spectra, and ion exchange capability were also determined. Cr(VI) adsorbed onto the NAZ1 surface was easily desorbed using a sodium hydroxide solution under our experimental conditions. The information regarding this study can be useful for removing Cr(VI) from aqueous media.

scholarly journals Chromium Metal Biosorption Using Peanut Shell Adsorbent

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Siti Annida ◽  
Inayati Inayati ◽  
Fera Setiawati
Keyword(s):  
Adsorption Mechanism ◽  
Sodium Hydroxide Solution ◽  
Chromium Concentration ◽  
Peanut Shell ◽  
Negative Effects ◽  
Industrial Growth ◽  
Chromium Vi ◽  
Metal Biosorption ◽  
Chromium Adsorption ◽  
Good Agreement

<p>One of the negative effects of the industrial growth is the presence of hazardous waste such as heavy metals. Chromium (VI) is a heavy metal which acts as the pollutant for  the  environment. Chromium concentration in  water  can  be  reduced using some methods. Adsorption is the most favorite method. Some of the biomass can be processed into adsorbent. This work was aimed to produce biosorbent from peanuts shell. The adsorbent was then used to adsorb chromium contented in water. Sodium hydroxide solution 0.5 M was used to activate peanut shell. Produced biosorbent was characterized using Fourier Transform Infrared Spectroscopy. The results showed that optimum condition for chromium adsorption was achieved at 30 minutes contact time with maximum adsorbed chromium of 0.022 mg/g adsorbent. The adsorption mechanism was in a good agreement with Langmuir isotherm.</p>

scholarly journals Removal of Arsenic(III) Ion from Aqueous Media Using Complex Nickel-Aluminum and Nickel-Aluminum-Zirconium Hydroxides

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1697 ◽  
Author(s):  
Fumihiko Ogata ◽  
Noriaki Nagai ◽  
Megumu Toda ◽  
Masashi Otani ◽  
Chalermpong Saenjum ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Aqueous Media ◽  
Correlation Coefficients ◽  
Nickel Aluminum ◽  
Metal Hydroxides ◽  
Sulfate Ions ◽  
Removal Of Heavy Metals ◽  
Removal Of Arsenic ◽  
Complex Nickel

The technology of wastewater treatment involving removal of heavy metals using complex metal hydroxides is reported. In this study, complex nickel-aluminum (NA11 and NA12) and nickel-aluminum-zirconium (NAZ1 and NAZ2) hydroxides were prepared for the removal of arsenite ions, As(III), from aqueous solution. The characteristics of each adsorbent were evaluated, and the adsorption capacity and adsorption mechanism were determined. The adsorption capacity of As(III) on NAZ1 (15.3 mg g−1) was greater than that on NA11 (9.3 mg g−1). Coverage is directly related to the specific surface area with a correlation coefficient of 0.921. Ion exchange involving sulfate ions in the interlayer of the adsorbent also plays a role in the mechanism of As(III) adsorption as demonstrated by correlation coefficients of 0.797 and 0.944 for the NA11 and NAZ1, respectively. The results demonstrate the usefulness of NAZ1 in removing As(III) from aqueous media.

In vivo Production of Soluble Inorganic Pyrophosphatases in Two Strains of Vibrio cholerae

1970 ◽  
Vol 24 (1) ◽  
pp. 38-41
Author(s):  
Taslima Taher Lina ◽  
Mohammad Ilias
Keyword(s):  
Vibrio Cholerae ◽  
Specific Activity ◽  
Experimental Conditions ◽  
Environmental Strain ◽  
Cell Extracts ◽  
Atcc Strain ◽  
The Family ◽  
Effects Of Ph ◽  
Vibrio Cholerae O1

The in vivo production of soluble inorganic pyrophosphatases (PPases) was investigated in two strains, namely, Vibrio cholerae EM 004 (environmental strain) and Vibrio cholerae O1 757 (ATCC strain). V. cholerae is known to contain both family I and family II PPase coding sequences. The production of family I and family II PPases were determined by measuring the enzyme activity in cell extracts. The effects of pH, temperature, salinity of the growth medium on the production of soluble PPases were studied. In case of family I PPase, V. cholerae EM 004 gave the highest specific activity at pH 9.0, with 2% NaCl + 0.011% NaF and at 37°C. The strain V. cholerae O1 757 gave the highest specific activity at pH 9.0, with media containing 0% NaCl and at 37°C. On the other hand, under all the conditions family II PPase did not give any significant specific activity, suggesting that the family II PPase was not produced in vivo in either strains of V. cholerae under different experimental conditions. Keywords: Vibrio cholerae, Pyrophosphatases (PPases), Specific activityDOI: http://dx.doi.org/10.3329/bjm.v24i1.1235 Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 38-41

scholarly journals Ferroxidase activity of ferritin: effects of pH, buffer and Fe(II) and Fe(III) concentrations on Fe(II) autoxidation and ferroxidation

1999 ◽  
Vol 338 (3) ◽  
pp. 615-618 ◽  
Author(s):  
Xiaoke YANG ◽  
N. Dennis CHASTEEN
Keyword(s):  
Ph Control ◽  
Alternative Mechanism ◽  
Experimental Conditions ◽  
Iron Storage ◽  
Ferroxidase Activity ◽  
Effects Of Ph ◽  
Ph Stat ◽  
Ph Buffer ◽  
Horse Spleen Ferritin

It is widely accepted that iron deposition in the iron storage protein ferritin in vitro involves Fe(II) oxidation, and that ferritin facilitates this oxidation at a ferroxidase site on the protein. However, these views have recently been questioned, with the protein ferroxidase activity instead being attributed to autoxidation from the buffer alone. Ligand exchange between another protein with ferroxidase activity and ferritin has been proposed as an alternative mechanism for iron incorporation into ferritin. In the present work, a pH stat apparatus is used to eliminate the influence of buffers on iron(II) oxidation. Here we show that the recent experiments questioning the ferroxidase activity of ferritin were flawed by inadequate pH control, that buffers actually retard rather than facilitate iron(II) oxidation, and that horse spleen ferritin has ferroxidase activity when measured under proper experimental conditions. Furthermore, high pH (7.0), a high Fe(II) concentration and the presence of Fe(III) all favour Fe(II) autoxidation in the presence or absence of ferritin.

The physicochemical and DNA binding studies of some medicinal compounds in solutions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Abbas Khan ◽  
Naila ◽  
Muhammad Humayun ◽  
Muhammad Sufaid Khan ◽  
Luqman Ali Shah ◽  
...  
Keyword(s):  
Flow Behavior ◽  
Aqueous Media ◽  
Research Work ◽  
Binding Constants ◽  
Physicochemical Study ◽  
Solution Temperature ◽  
Binding Studies ◽  
Experimental Conditions ◽  
Medicinal Compounds ◽  
Association Behavior

Abstract To understand the expected mode of action, the physicochemical study on the solution properties of medicinal compounds and their interaction with deoxyribonucleic acid (DNA), under varying experimental conditions, is of prime importance. The present research work illustrates the physicochemical study and interaction of certain medicinal compounds such as; Levofloxacin, Ciprofloxacin, and Ibuprofen with DNA. Density, viscosity and surface tension measurements have been performed in order to determine, in a systematic manner, the physicochemical, volumetric and thermodynamic properties of these compounds; and most of these parameters have shown different behavior with varying concentration of solution, temperature of the medium and chemical nature/structure of the compound. In addition, these drugs showed a spontaneous surface-active and association behavior in aqueous solutions. The flow behavior, surface properties, volumetric behavior and solute–solvent interaction of these drugs were prominently influenced by experimental variables and addition of DNA to their solutions. UV–Visible spectroscopy was also used to examine the interaction of these drugs with DNA in aqueous media in detail. Calculated values of binding constants (Kb) for all complexes of drug-DNA are positive, indicating a fruitful binding process. It is seen that a smaller Kb value reflects weaker binding of the drug with DNA and vise versa. Due to the difference in the chemical structure of drugs the values of binding constant are different for various drug-DNA complexes and follow the order Kb(Levofloxacin-DNA) > Kb(Ciprofloxacin-DNA) > Kb(Ibuprofen-DNA). On the basis of spectral changes and Kb it can be said that the binding of all these drugs with DNA may be of physicochemical nature and the dominating binding force be of hydrogen bonding between oxygen of drugs and hydrogen of DNA units and the drug having more oxygen atoms showed stronger binding ability. The data further suggest a limited possibility of chemical type attachment of these drugs with DNA.

Free-base corroles: determination of deprotonation constants in non-aqueous media

2007 ◽  
Vol 11 (04) ◽  
pp. 269-276 ◽  
Author(s):  
Jing Shen ◽  
Zhongping Ou ◽  
Jianguo Shao ◽  
Michał Gałęzowski ◽  
Daniel T. Gryko ◽  
...  
Keyword(s):  
Equilibrium Constants ◽  
Aqueous Media ◽  
Free Base ◽  
Organic Base ◽  
Experimental Conditions ◽  
Spectral Changes ◽  
Base Analysis ◽  
Uv Visible ◽  
The Given

A series of free-base corroles with different electron-donating or electron-withdrawing substituents were reacted with piperidine, 4-aminopyridine, 2-methylimidazole, 2-aminopyridine or pyridine in PhCN and the UV-visible spectral changes monitored during conversion of ( Cor ) H 3 to [( Cor ) H 2]- as a function of the concentration and strength of the added organic base. Analysis of the UV-visible spectral changes as a function of the added base concentration enabled calculation of equilibrium constants ( logK ) for deprotonation of each corrole under the given experimental conditions. Relationships are examined between the experimentally measured logK values and previously published spectroscopic and structural properties of the compounds.

scholarly journals Iodination of insulin in aqueous and organic solvents

1969 ◽  
Vol 115 (1) ◽  
pp. 11-18 ◽  
Author(s):  
A. Massaglia ◽  
U. Rosa ◽  
G. Rialdi ◽  
C. A. Rossi
Keyword(s):  
Ethylene Glycol ◽  
Organic Solvents ◽  
Molecular Conformation ◽  
Aqueous Media ◽  
Native Structure ◽  
Experimental Conditions ◽  
Polar Environment ◽  
Polar Area ◽  
The Difference ◽  
A Chain

1. The iodination of insulin was studied under various experimental conditions in aqueous media and in some organic solvents, by measuring separately the uptake of iodine by the four tyrosyl groups and the relative amounts of monoiodotyrosine and di-iodotyrosine that are formed. In aqueous media from pH1 to pH9 the iodination occurs predominantly on the tyrosyl groups of the A chain. Some organic solvents increase the iodine uptake of the B-chain tyrosyl groups. Their efficacy in promoting iodination of Tyr-B-16 and Tyr-B-26 is in the order: ethylene glycol and propylene glycol≃methanol and ethanol>dioxan>8m-urea. 2. It is suggested that each of the four tyrosyl groups in insulin has a different environment: Tyr-A-14 is fully exposed to the solvent; Tyr-A-19 is sterically influenced by the environmental structure, possibly by the vicinity of a disulphide interchain bond; Tyr-B-16 is embedded into a non-polar area whose stability is virtually independent of the molecular conformation; Tyr-B-26 is probably in a situation similar to Tyr-B-16 with the difference that its non-polar environment depends on the preservation of the native structure.

scholarly journals Removal of Chromium (VI) cation metal using Poly (N-vinyl-2-pyrrolidone)/Magnetite nanocomposite from aqueous media

2017 ◽  
Vol 13 (10) ◽  
pp. 5886-5891
Author(s):  
Padmalaya G ◽  
Sreeja BS ◽  
Radha S ◽  
Raamdheep G ◽  
Saranya J
Keyword(s):  
Magnetite Nanoparticles ◽  
Infrared Absorption Spectrum ◽  
Aqueous Media ◽  
Polyvinyl Pyrrolidone ◽  
Human Society ◽  
Promising Alternative ◽  
Chromium Vi ◽  
Ir Studies ◽  
Vis Spectroscopy ◽  
Co Precipitation

Groundwater contamination with heavy metals is considered as serious environmental hazard that affect the human society. Nano adsorbents incorporating magnetite nanoparticles provides promising alternative to facilitate removal of heavy metal ions from wastewater. The present work focuses on removal of chromium (VI) cationic metals from aqueous media using Polyvinyl Pyrrolidone (PVP)/Magnetite (Fe3O4) Nanocomposite (MNC). Magnetite nanoparticles are synthesized using chemical co-precipitation and grafted using polyvinyl pyrrolidone to form a magnetite nanocomposite. MNC were characterized with X-ray diffraction (XRD) and Infrared absorption spectrum (FT-IR) studies to affirm the formation and presence of polymeric functional groups of PVP/Magnetite nanocomposite. Batch experiments are carried out at exclusive concentration intervals to study about the adsorption efficiency of MNC on chromium (VI) cationic metal using U-Vis spectroscopy. The results obtained through adsorption studies shows the synthesized PVP/Magnetite nanocomposites has a removal efficiency of 94%.

scholarly journals Reduction of chromium (VI) from aqueous solution by biomass of Cladosporium cladosporioides

2017 ◽  
Vol 76 (9) ◽  
pp. 2494-2502 ◽  
Author(s):  
María Teresa Garza-González ◽  
Jonathan Eduardo Ramírez-Vázquez ◽  
María de los Ángeles García-Hernández ◽  
María Elena Cantú-Cárdenas ◽  
Adriana Liñan-Montes ◽  
...  
Keyword(s):  
Reduction Process ◽  
Cladosporium Cladosporioides ◽  
Total Chromium ◽  
Isothermal Model ◽  
Process Comparison ◽  
Chromium Vi ◽  
Before And After ◽  
Effects Of Ph ◽  
Pseudo Second Order ◽  
Adsorption Reduction

Abstract The capacity of Cladosporium cladosporioides biomass for removal of Cr(VI) in aqueous solutions was evaluated. A 2 × 2 factorial experiment design was used to study the effects of pH and biomass doses. Lower pH values and larger biomass doses increased the capacity of C. cladosporioides biomass for removal of Cr(VI), reaching a reduction capacity of 492.85 mg g−1, a significantly higher value compared to other biomass reported. Cr(VI) removal kinetic rates followed a pseudo-second order model, like other fungal biomass reported previously. The apparent adsorption process was described well by the Freundlich isothermal model. However, determination of total chromium indicated that adsorption of Cr(VI) was followed by a redox reaction that released proportional quantities of Cr(III) into the experimental supernatant, suggesting a parallel adsorption-reduction process. Comparison of Fourier transform infrared spectroscopy spectra of C. cladosporioides biomass before and after the reduction process demonstrated the involvement of positively charged amino groups in the Cr(VI) adsorption-reduction process.

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