Dielectric spectroscopic evaluation in the extremely low frequency range of an Aspergillus niger culture

Abstract

By using the dielectric spectroscopy technique in the extremely low frequency (1-200Hz) range, dielectric loss tgδ was determined on both Aspergillus niger cultures in different growth stages and autoclaved biomass compared to the Czapex-Dox culture medium with sterile sucrose. Experimental results have shown that living and sterile matter samples have different dielectric characteristics. In sterile probes, the evolutionary functions of tgδ depending on frequency are continuous, specific to αrelaxation governed by DC electrical conductivity. In living matter samples, the function of dielectric losses tgδ, depending on frequency, show several discontinuities that indicate the existence of some processes in which, at those frequencies, the number of charge carriers from investigated living matter is changing. It has also been found that the package of active processes differs depending on the growth stage of Aspergillus niger.

Electromagnetic Stimulation of Microbial Activity in Wastewater Treatment: Experimental Equipment

“…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 .…”

The Energy Efficiency of Domestic Wastewater Treatment Processes: Case Analysis

“…The results of recent experimental investigations [41]- [44] suggest that the microbiological activity can also be stimulated by exposing biomass to an extremely low-frequency electromagnetic field (ELF). In this context, we propose the experimental development and implementation of a system to spur the biological treatment stages by exposing the biomass in the ELF field at a specific frequency, according to [41], [42], [54] at the wastewater treatment plant in Romuli.…”

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

“…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.…”