2020 Volume 49 Issue 2 Pages 91-97
The filtration efficiency of the hydroxyapatite powder cake filtration method, which was developed as a concentration method for protozoa, such as Cryptosporidium, was evaluated as an Escherichia coli concentration method. When pond water was used as a sample, this method could filtrate 2 to 2.5 times more water than a ∅47 ㎜ cellulose-mixed ester filter（pore size 0.22 or 0.45 µm）or a polycarbonate filter（0.2 µm）alone. Additionally, there was a high recovery rate of E. coli from the concentrate. In E. coli enumeration using actual river water, sewage, and effluents, E. coli concentrations equal to or higher than the conventional membrane filter method were achieved. This method enables the easy processing of volumes exceeding 100 mL and applies in liquid media, such as the Colilert method, for which no appropriate concentration methods were present previously.
