2. Artificial Self-Purification of Sewage in Intermittent Contact Beds.
At the outset it may not be out of place to make a few remarks concerning the various names given to this form of application. The term “intermittent contact bed” is here used to distinguish this kind of bed from the “continuous contact bed,” frequently called “continuous filtration.”
Names of process misleading.
(a) Name of Process.—This process has frequently been called “biological process,” “bacteriological process,” “contact bed system” or “oxidation bed system,” but all these terms do not appear to define it sufficiently, as they do not cover the whole, but only phases or stages in the same; hence, they do not seem appropriate.
Biological process.
The name “biological process” is decidedly misleading, for besides biological agencies there are also at work physical (mechanical) and chemical ones.
Bacteriological process.
The term “bacteriological or bacterial process” is likewise erroneous, for besides bacteria a number of other micro-organisms participate in it—such as yeast
fungi, mould fungi, algæ, protozoa, and even higher forms of life, such as earthworms and insects.
Contact bed system.
Oxidation bed system.