Thermodynamic evaluation of the corrosion-electrochemical behaviour of silicon bronzes

The removal of Cd(II) and Pb(II) ions from aqueous medium was studied using potato peels biomass. The adsorption process was evaluated using Atomic Absorption Spectrophotometer (AAS). The Vibrational band of the potato peels was studied using Fourier Transform Infrared Spectroscopy (FTIR). The adsorption process was carried out with respect to concentration, time, pH, particle size and the thermodynamic evaluation of the process was carried at temperatures of 30, 40, 50 and 60(0C), respectively. The FTIR studies revealed that the potato peels was composed of –OH, -NH, –C=N, –C=C and –C-O-C functional groups. The optimum removal was obtained at pH 8 and contact time of 20 min. The adsorption process followed Freundlich adsorption and pseudo second-order kinetic models with correlation coefficients (R2) greater than 0.900. The equilibrium adsorption capacity showed that Pb(II) ion was more adsorbed on the surface of the potato peels biomass versus Cd (II) ion (200.91 mg/g > 125.00 mg/g). The thermodynamic studies indicated endothermic, dissociative mechanism and spontaneous adsorption process. This study shows that sweet potato peels is useful as a low-cost adsorbent for the removal of Cd(II) and Pb(II) ions from aqueous medium.

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Discovery of THICZs as Chemical Sensors: Synthesis, Spectrophotometric,Voltammetric and DFT Studies

International Journal of Sensors Wireless Communications and Control ◽

10.2174/2210327909666190710101420 ◽

2019 ◽

Vol 09 ◽

Author(s):

Mardia T. El Sayed ◽

Ibrahim H.I. Habib ◽

Nermien M. Sabry ◽

Sergey A. Pisarev ◽

Mohamed El-Naggar ◽

...

Keyword(s):

Electrochemical Behaviour ◽

Molecular Size ◽

Active Species ◽

Carbon Paste ◽

Reversible Redox ◽

Energy Relationships ◽

Linear Solvation Energy ◽

Solute Interactions ◽

Homo Lumo ◽

Paste Electrode

Absorption spectra of tetrahydro[3,2-b]indolo-carbazoles (THICZs) with various molecular size and alkyl tails have been recorded in various solvents in the range between 200 to 600 nm. The photo physical behaviour of dissolved THICZs depends on the nature of its environment. The solvatochromic behaviours of THICZs and solvent solute interactions can be analysed by means of linear solvation energy relationships concept proposed by Kamlet and Taft. Compound 4 show excellent properties for sensing small molecules. The electrochemical behaviour of some THICZs was investigated at carbon paste electrode where two electrode reactions were involved, irreversible oxidation-one electron transfer and quasi-reversible redox reactions forming phenolic followed by quinolone moiety electro active species. The DFT-calculated molecular orbital energies (B3LYP/6-31G) and HOMO-LUMO gaps for some presented indolocarbazoles have been performed.

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Kinetic, equlibrium, and thermodynamic evaluation of zinc, cobalt, and nickel ions removal from aqueous solution By modified biomass of asperigillus flavus

International Journal of Pharma and Bio Sciences ◽

10.22376/ijpbs.2017.8.1.b304-315 ◽

2017 ◽

Vol 8 (1) ◽

Author(s):

RAUF FOROUT AN ◽

SIMA FARJAD FARD ◽

BAHMAN RAMAV ANDI

Keyword(s):

Aqueous Solution ◽

Thermodynamic Evaluation ◽

Nickel Ions ◽

Cobalt And Nickel

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Electrochemical behaviour and ESR spectra of nitro substituted mono- and dibenzoylmethylenebenzthiazolines and selenazolines

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19791540 ◽

1979 ◽

Vol 44 (5) ◽

pp. 1540-1551 ◽

Cited By ~ 3

Author(s):

Jaro Komenda ◽

Jiří Huzlík

Keyword(s):

Electron Transfer ◽

Esr Spectroscopy ◽

Electrochemical Behaviour ◽

Spectroscopic Studies ◽

Esr Spectra ◽

Slow Electron

Compounds of the type of 2-(4'-nitrobenzoyl)methylene-3-ethylbenzothiazoline (I) and 2-bis-(p-nitrobenzoyl)methylene-3-ethylbenzothiazoline (II) were studied polarographically and by ESR spectroscopy to obtain informations about their electrochemical and follow-up reactions and their conformation. Whereas with compounds of the type I the conjugation in their molecules is preserved, with type II the coplanarity of the molecules is disturbed, which is manifested in the values of the splitting constants of the ESR spectra and a slow electron transfer between both nitrophenyl substituents. These conclusions are supported by NMR spectroscopic studies.

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