THE AC/TC BACTERIAL RATIO: A TOOL FOR WATERSHED QUALITY MANAGEMENT
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概要
- 論文の詳細を見る
An inexpensive tool for indicating microbial quality in watersheds is presented that utilizes the conventional total coliform test, comparing the relative concentrations of different colonies that form on a membrane filter fed by m-Endo media. These bacterial colonies can be classified into 3 types; typical (TC), atypical (AC), and background. The ratio of the concentrations of AC colonies to those of TC is related to water quality, fecal loadings, and fecal age. The AC/TC ratio relies upon shifts in populations between indigenous and introduced bacteria, with the indigenous bacteria providing a baseline against which the concentrations of the introduced are evaluated. When the AC/TC ratio is low (<5), fresh fecal material is in the water and pathogen risk can be expected to be higher. As time passes, the AC/TC ratio increases (>20) and can be related to healthier water quality conditions. Different types of runoff have different AC/TC values with human sewage at the lowest end of the spectrum with a value of 1.5 under normal conditions.
- Japan Society on Water Environmentの論文