Abstract
The adhesion of biofilm to the microscopic part, or the thermal microhabitat on the heated media was studied to establish an effective water purification process at low water temperature. The circular tube was used as filter media for simplicity of both the experimental operation and the theoretical development to which the theory of the convection heat transfer at laminar flow was applied. Major conclusions obtained in this study were as follows : (1) The rise of water temperature by the heated media was a function of the surface area of media, the heat flux from media surface and the flow rate. (2) It was confirmed that the adhesion of the biofilm was brought about on the surface of the heated media, where the raw water at low temperature flew at laminar flow and the microscopic part was kept at higher temperature. (3) The mean thickness of the biofilm was computed using the water temperature in influent and effluent, and the flow rate. The calculated value was found to agree approximately with the result observed using the scanning electron microscope at the end of the experimental period. (4) It was found that there were few differences in the surface temperature of the heated media and the biofilm which thickness was about 35μm. Thus, the temperature in the biofilm was considered to be constant.
