The purpose of this experiment is to determine the optimum conditions for precoating and to study the physical properties by increasing the thickness of the precoat.
The filtering abilities of Diatomite filter-aid and Koralin A were tested by filtering the liquid containing E. coli 0111.
The Ultra Filter, belonging to leaf type, made by the Miura Chemical Machinery Co. in Japan, was used in this experiment.
The filter-aids used were Koralin A, Diatomite filter-aid, Hyflo super cel and Standard super cel.
Some results obtained were as follows : （1） Precoating data of various filter-aids (2) When Diatomite Filter-aid was used, the shape of the particles was broken at the pressure of 1.6 kg/cm² in the precoating test. (3) In the case of E. coli 0111 filtration, Koralin A was compared with Diatomite filter-aid, and Korolin A was found to be better than Diatomite as the filter aid, but in the former the flow rate was lower.