Spectroscopic Manifestation of Interaction of Humic Acids with Ferric Ions in Aqueous Solutions

AbstractConformational changes in humic acids in two different aqueous solutions (NaCl and NaOH) are studied by means of high resolution ultrasound spectrometry. The method is based on the measurement of parameters of ultrasonic waves propagating through the sample. The attenuation describes the decay of the amplitude of the ultrasonic wave with the distance travelled. The velocity is the speed of this wave and is related to the wavelength and the frequency of oscillation of the deformation. It is determined by the density and elasticity of the sample, which is strongly influenced by the molecular arrangement. The minimal velocity of ultrasound was observed at 1 g dm−3 for lignitic humic acids and at 0.5 g dm−3 for IHSS Leonardite standard. The values of compressibility as computed are almost constant up to humic acids’ content corresponding to the minimum velocity of ultrasound and then decrease with the increase in concentration. This shows that the organisation of particles in diluted and concentrated humic acids sols is different. The decrease in compressibility points to the formation of a more rigid structure, which could lead to the decrease in humic acids’ binding ability. It was confirmed that the method employed was very sensitive and could be utilised as an indicator of conformational changes in humic acids in solutions with varying concentrations.

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Magnetic field dependence of the spin—spin relaxation time of ferric ions in Fe(NO3)3·9H2O and in frozen aqueous solutions

Chemical Physics Letters ◽

10.1016/0009-2614(73)80158-7 ◽

1973 ◽

Vol 21 (2) ◽

pp. 363-367 ◽

Cited By ~ 22

Author(s):

S. Mørup ◽

N. Thrane

Keyword(s):

Magnetic Field ◽

Relaxation Time ◽

Aqueous Solutions ◽

Field Dependence ◽

Spin Relaxation ◽

Magnetic Field Dependence ◽

Spin Relaxation Time ◽

Ferric Ions

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Impact of humic acids on fluorimetric determination of phenol in aqueous solutions

Journal of Water Chemistry and Technology ◽

10.3103/s1063455x16020089 ◽

2016 ◽

Vol 38 (2) ◽

pp. 106-110

Author(s):

S. A. Dolenko ◽

A. M. Kravchenko ◽

G. N. Pshinko

Keyword(s):

Aqueous Solutions ◽

Humic Acids ◽

Fluorimetric Determination

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Structure and phase behavior of poly(acrylic acid)–ferric ion complex aqueous solutions

Soft Matter ◽

10.1039/d0sm01461c ◽

2020 ◽

Vol 16 (47) ◽

pp. 10750-10758

Author(s):

Yingchun Han ◽

Xinyue Zhao ◽

Yonggang Liu ◽

Yunqi Li ◽

Quan Chen

Keyword(s):

Acrylic Acid ◽

Aqueous Solutions ◽

Phase Behavior ◽

Small Angle ◽

Ferric Ion ◽

Ferric Ions ◽

Ph Measurements ◽

X Ray ◽

X Ray Scattering ◽

Poly Acrylic Acid

In this study, we investigate the conformational evolution and phase behavior of poly(acrylic acid) (PAA) solution upon the introduction of ferric ions through combining of small angle X-ray scattering (SAXS), turbidity, ζ-potential and pH measurements.

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