Effect of Microwave Radiation on Regeneration of a Granulated Micelle–Clay Complex after Adsorption of Bacteria

Abstract

Granulated micelle–clay complexes including the organic cation octadecyltrimethylammonium (ODTMA) were shown to be efficient in removal of total bacteria count (TBC) from water. Microwave (MW) heating of granules to restore bacterial removal was investigated. Drying of granules by MW required 20-fold less energy than by conventional heating. When water content of granules approached 10%, or less, their heating period by MW had to be below 1 min, e.g., 30 s, and less, in order to avoid ignition and irreversible structural changes. Structural and thermal properties of MW heated samples were studied by FT-IR spectra and thermo gravimetric analyses (TGA). Inactivation of bacteria in water was more efficient by MW than by conventional oven, or by electric plate. For elimination of bacteria from water, MW heating was at least five-fold more efficient than by conventional heating. The results have established an adequate regeneration procedure by MW heating at durations depending on the remaining percentage of water associated with the granules. Tests of first and second regenerations by MW heating, and HCl washing of columns, were carried out. It was concluded that MW treatment may be chosen for optimal regeneration of the granulated micelle–clay complex as an efficient and low-cost procedure.

Removal of Emerging Contaminants by Degradation during Filtration: A Review of Experimental Procedures and Modeling

“…If the allowed value of the given pollutant for being spilled into the environment corresponds to 0.45 C 0 , then the capacity of this filter is 28.8 L, which amounts to 28.8/400 L/g. When regenerated by an optimized procedure based on microwave heating, as in [14], the capacity can be tripled to 0.22 (m 3 /kg), which is rather low. When a procedure augmented by degradation with kd = 0.01 min −1 is employed, the calculated results in Table 1 indicate that after 10 h of operation, the value of C/C 0 is just 0.041 or C = 0.041C 0 up to 5 d, and in fact, for longer times, implying a very large capacity.…”

“…It should be noted that the sterilization of the GAC was conducted once a week in order to avoid the development of toxin-degrading bacteria in the filter. The process of sterilization of the GAC involved autoclaving at 121 • C. In [14,46], the heating of the used filter material was carried out as an efficient regeneration, which restored most of its adsorption capacity. During the first stages of removal via degradation during filtration, most of the removal occurs by adsorption rather than by degradation.…”

Clay-Polymer Nanocomposites: Preparations and Utilization for Pollutants Removal

“…However, nowadays, this technology becomes less used due the existence of soluble organic pollutants that allowed the formation of secondary toxic contaminants (chlorophenols, haloacetic acids, trihalomethanes, etc.) [ 41 ]. Also, chloramination process showed a higher potential to form nitrosamines than chlorination.…”

On the Wireless Microwave Sensing of Bacterial Membrane Potential in Microfluidic-Actuated Platforms

“…The result is that power is dissipated and the material consequently heats up. This phenomenon is known as the dipolar polarization mechanism and is the basis of microwave dielectric heating [ 61 ]. The heat produced can be quantified from the average power dissipated as described in [ 5 ], where ω is the angular frequency, is relative loss factor of the cell, is the dielectric constant of the vacuum, and is the incident field.…”