Modeling relaxation processes and investigating the dispersion of low-frequency phenomena (LFD) in urban wastewater were conducted using an equivalent circuit. These wastewater streams are discharged without undergoing any prior treatment, were used for irrigating fields near a lake in the agricultural region of Doukkala, Morocco. The samples were collected from three different sites and underwent standard physicochemical and bacteriological assessments using conventional methods in the first step. In the second step, the results of impedance spectroscopy measurements were simulated and discussed in the frequency range spanning from 102 mHz to 10–1 MHz. In the permittivity spectrum, the results show the relaxation processes at higher frequency concerning the condensed counter-ions and LFD processes at low frequency concerning the free charges. Moreover, in the modulus spectrum, the relaxation process was detected at a low frequency created by the free charges. The equivalent circuit parameters, such as the relaxation time <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41207_2025_887_Article_IEq1.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="23" /> </InlineMediaObject> <EquationSource Format="TEX">$\left( \tau \right)$</EquationSource> <EquationSource Format="MATHML"><math> <mfenced close=")" open="("> <mi>τ</mi> </mfenced> </math></EquationSource> </InlineEquation> and dielectric strength (Δε) were decreased of the samples more polluting to the less polluting. Whereas, the hopping conductivity (<InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41207_2025_887_Article_IEq2.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">$\sigma ho$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>σ</mi> <mi>h</mi> <mi>o</mi> </mrow> </math></EquationSource> </InlineEquation>) was increased with the polluting charges increase. A good correlation between dielectric parameters and physicochemical parameters was investigated to comprehend the contaminant behavior in water.

Modeling of relaxation processes and low frequency dispersion of wastewater using an electrical equivalent circuit

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2025年8月11日

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E. Chahid,
A. Mortadi,
R. Mghaiouini,
T. Garmim,
K. Mnaouer,
Y. Hairech,
A. Elmelouky,
S. Laasri,
R. El Moznine,
M. Monkade

摘要

Modeling relaxation processes and investigating the dispersion of low-frequency phenomena (LFD) in urban wastewater were conducted using an equivalent circuit. These wastewater streams are discharged without undergoing any prior treatment, were used for irrigating fields near a lake in the agricultural region of Doukkala, Morocco. The samples were collected from three different sites and underwent standard physicochemical and bacteriological assessments using conventional methods in the first step. In the second step, the results of impedance spectroscopy measurements were simulated and discussed in the frequency range spanning from 10² mHz to 10^–1 MHz. In the permittivity spectrum, the results show the relaxation processes at higher frequency concerning the condensed counter-ions and LFD processes at low frequency concerning the free charges. Moreover, in the modulus spectrum, the relaxation process was detected at a low frequency created by the free charges. The equivalent circuit parameters, such as the relaxation time $\left( \tau \right)$ $(τ)$ and dielectric strength (Δε) were decreased of the samples more polluting to the less polluting. Whereas, the hopping conductivity ( $\sigma ho$ $σ h o$ ) was increased with the polluting charges increase. A good correlation between dielectric parameters and physicochemical parameters was investigated to comprehend the contaminant behavior in water.