Investigation of Combined Influence of Super-High-Frequency Electromagnetic Radiation on the Sewage Sediment Properties

Microwave Irradiation in Technologies of Wastewater and Wastewater Sludge Treatment: A Review

“…Table 5 shows variations in the physical and chemical properties of WWS under the influence of MW (frequency f = 2.45 GHz); the results have been derived from batch experiments. Some publications [25,34,36] provide evidence of changes in the structure of wastewater sediments under the influence of MW irradiation. Microwave processing of activated sludge has a tipping point: up to a certain length at a constant strength, the flakes firstly expand (for example, at 900 W for the first one to two minutes), then the more extended process (over two minutes) destroys them [25].…”

“…Microwave processing of activated sludge has a tipping point: up to a certain length at a constant strength, the flakes firstly expand (for example, at 900 W for the first one to two minutes), then the more extended process (over two minutes) destroys them [25]. At the same time, the structure becomes more homogeneous and dispersed [36].…”

“…A change in the spatial configuration of samples of a sediment mixture after MW heating to a temperature of 75 °C [34,36] was observed during a microbiological analysis using an electron microscope Micromed 2 (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Figure 4 The initial structure of the sediment flakes (Figure 4a) is uneven, coarse-dispersed, with separate large conglomerates, saturated with protozoan bacteria.…”

“…After microwave heating, the effect of reduced resistivity retains. Analysis of a series of experiments showed that MW treatment of sewage sludge during four minutes at a power of 800 W significantly reduces the specific resistance of filtration: the initial sludge average value of resistance is 37.15 ×10 −10 cm/g with an allow for an error of no more than 10%, after microwave treatment it is 6.93 ×10 −10 cm/g [34,36]. Under the further remained heating, the viscosity and resistivity can rise due to excessive evaporation after a turning point at a certain power and length of MW-treatment, which are calculated separately for each form of WWS [25].…”

“…Many scientists conduct experiments in home microwave ovens or reactors based on them or in modular laboratory systems [8,14,36,90,108,110].…”