Dielectric behavior of sludge from waste water treatment

Bartha, Csaba; Caramitu, Alina Ruxandra; Jipa, Monica; Ignat, D.; Tokos, Attila

doi:10.24193/subbchem.2020.4.07

Cited by 13 publications

(4 citation statements)

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“…Also, from the studies performed by the dielectric spectroscopy technique [50]- [52], it resulted that the stimulation takes place only at certain representative ("sensitive") frequencies. These results are in good agreement with the results of the in-depth studies reported [53].…”

Section: Stimulation Of Microbial Activity By Elf Electromagnetic Fieldmentioning

confidence: 99%

“…Laboratory measurements performed through dielectric spectroscopy technique on activated sludge sampled from various sources (treatment plants) highlighted a common element, namely that biomass can be stimulated at a frequency of 50±50 Hz [50], [52], "sensitive" frequency, also found in Aspergillus Niger cultures [44], [51]. Laboratory measurements reported in [50] show that the biostimulation of the microorganisms from activated sludge is achieved with maximum efficiency in a field of 4-5 V/m, which in domestic wastewater takes place at a current density of up to 0.6 A/m 2 .…”

Section: The Power Supplymentioning

confidence: 99%

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Electromagnetic Stimulation of Microbial Activity in Wastewater Treatment: Experimental Equipment

Tokos¹,

Jipa²,

Marinescu³

et al. 2021

EEA

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A system for electromagnetic stimulation of microorganisms' activity from the active sludge of wastewater treatment plants was developed and preliminarily tested. Through electrochemical, gravimetric, XRD, and SEM-EDAX measurements, it was found that austenitic stainless steel 18/8 presents good stability to AC polarization in wastewater. Preliminary determinations performed through the dielectric spectroscopy technique indicated that the activated sludge's microbial flora is sensitive to 50 ± 0.1 Hz. The stimulation system developed and put into service on the biological aerobic treatment bioreactor consists of a pair of polarizing electrodes, made of perforated 18/8 stainless steel sheet, electrically connected to a power supply, which at 50 Hz is capable of debiting adjustable voltages between 5 and 24 Vrms at a maximum current of 5 A. Preliminary in situ measurements showed that following the stimulation of the microorganisms from the sludge suspension, as a result of an applied electromagnetic field of approximately 4.5 V/m at 50 Hz, the metabolism of residues is accelerated substantially (organic residues determined by oxygen demand decrease by about 42 %, nitrogen/ammonium content by about 44% and total phosphorus by about 50 % which results in an increase in free oxygen concentration by about 71 %).

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Section: Stimulation Of Microbial Activity By Elf Electromagnetic Fieldmentioning

confidence: 99%

Section: The Power Supplymentioning

confidence: 99%

Electromagnetic Stimulation of Microbial Activity in Wastewater Treatment: Experimental Equipment

Tokos¹,

Jipa²,

Marinescu³

et al. 2021

EEA

Self Cite

View full text Add to dashboard Cite

show abstract

“…Electromagnetic radiation pollution can lead to damage to human health [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ] and living matter [ 12 , 13 , 14 , 15 , 16 ], so it is urgently necessary to reduce it by researching and designing different new materials effective for this purpose. These materials must synergistically ensure a good attenuation of electromagnetic waves [ 17 , 18 ] and high resistance to the action of fungi [ 12 , 13 , 14 , 15 , 16 , 19 , 20 ], environmental conditions [ 21 , 22 , 23 , 24 , 25 , 26 ], mechanical stresses [ 27 , 28 ], excellent dielectric, magnetic and electromagnetic characteristics [ 29 , 30 , 31 , 32 ], and high resistance to the action of microwaves and UV radiation [ 33 ]. These conditions can be ensured through polymer-based composite materials, which have excellent mechanical properties and thermal stability, as well as high resistance to environmental conditions.…”

Section: Introductionmentioning

confidence: 99%

Recycled Polypropylene/Strontium Ferrite Polymer Composite Materials with Electromagnetic Shielding Properties

Caramitu,

Lungu,

Ciobanu

et al. 2024

Polymers

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This paper presents the obtaining and characterization of recycled polypropylene/strontium ferrite (PP/SrFe12O19) polymer composite materials with applications in the electromagnetic shielding of vehicle interiors (mainly automotive electronics—carcasses) from the electromagnetic radiation emitted mainly by exterior sources—electrical lines and supply sources—in terms of the development of the new electrical vehicles. With this aim, suitable polymer composite materials were developed using SrFe12O19 filler in two forms (powder and concentrate). The recycled PP polymer and composite materials with a PP/SrFe12O19 weight ratio of 75/25 and 70/30 were obtained in two stages, i.e., pellets by extrusion and samples for testing through a melt injection process. The characterization of the obtained materials took into account the requirements imposed by the desired applications. It consisted of determining the mechanical and dielectric properties, and microstructure analyses, along with the determination of the resistance to the action of a temperature of 70 °C, which is higher than the temperatures created during the summer inside vehicles. The performance of these materials as electromagnetic shields was assessed through functional tests consisting of the determination of magnetic permeability and the estimation of the electromagnetic shielding efficiency (SE). The obtained results confirmed the improvement of the mechanical, dielectric, and magnetic properties of the PP/SrFe12O19 composites compared to the selected PP polymers. It is also found that all the composite materials exhibited reflective shielding properties (SER from −71.5 dB to −56.7 dB), with very little absorption shielding. The most performant material was the composite made of PP/SrFe12O19 powder with a weight ratio of 70/30. The promising results recommend this composite material for potential use in automotive shielding applications against electromagnetic pollution.

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“…The continuous increase in electricity production, due to the ever-increasing demand of consumers, which generates electromagnetic fields, leads to an increase in the electromagnetic pollution of the environment in various rooms/spaces/offices [2]. Electromagnetic pollution, continuously increasing, can even lead to the deterioration of human health [3][4][5][6] and living matter [7][8][9][10][11][12][13][14]. Reducing the electromagnetic pollution created in different spaces with different uses can be achieved by researching and designing different new materials that are effective for this purpose [15,16].…”

Section: Introductionmentioning

confidence: 99%

Flexible Electromagnetic Shielding Nano-Composites Based on Silicon and NiFe2O4 Powders

Caramitu¹,

Ciobanu

Ion³

et al. 2023

Polymers

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In this paper, the obtaining and characterization of five experimental models of novel polymer composite materials with ferrite nano-powder are presented. The composites were obtained by mechanically mixing two components and pressing the obtained mixture on a hot plate press. The ferrite powders were obtained by an innovative economic co-precipitation route. The characterization of these composites consisted of physical and thermal properties: hydrostatic density, scanning electron microscopy (SEM), and TG DSC thermal analyses, along with functional electromagnetic tests in order to demonstrate the functionality of these materials as electromagnetic shields (magnetic permeability, dielectric characteristics, and shielding effectiveness). The purpose of this work was to obtain a flexible composite material, applicable to any type of architecture for the electrical and automotive industry, necessary for protection against electromagnetic interference. The results demonstrated the efficiency of such materials at lower frequencies, but also in the microwave domain, with higher thermal stability and lifetime.

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Dielectric behavior of sludge from waste water treatment

Cited by 13 publications

References 0 publications

Electromagnetic Stimulation of Microbial Activity in Wastewater Treatment: Experimental Equipment

Electromagnetic Stimulation of Microbial Activity in Wastewater Treatment: Experimental Equipment

Recycled Polypropylene/Strontium Ferrite Polymer Composite Materials with Electromagnetic Shielding Properties

Flexible Electromagnetic Shielding Nano-Composites Based on Silicon and NiFe2O4 Powders

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