MICROWAVE ENERGY TO THE HYGIENIZATION OF SEWAGE SLUDGE
Author: langfeng Time: 2019-03-06
The effectiveness of the destruction of microorganisms using microwaves depends on the time of exposure and the power of the electromagnetic field used. The influence of microwaves on microorganisms is the result of the thermal effect on water which is a part of their cytoplasm and the environment. It is also connected with nonthermal effects. The mechanism of non-thermal effect of microwaves on microorganisms is not precisely known. It is only known that it is not connected with breaking chemical bonds of substances from which microorganisms are built nor of compounds taking part in biochemical processes. The highest energy of microwave quantum equals 1.2 meV and is not adequate for breaking hydrogen bonds with the bond energy of 0.04–0.44 eV and covalent bonds (5 eV) .
The hygienization of sludge occurs during microwave heating. Salmonella and mesophilic bacteria are the most sensitive bacteria to microwave energy, whereas thermophilic bacteria and Clostridium demonstrate significant resistance to microwaves. Microwaves can be used as a highly efficient method of heating up sludge to the temperature necessary for its pasteurization.