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THE EFFECTS OF METHODS OF SEWAGE APPLICATION ON THE ECOLOGY OF BACTERIA BEDS
Author(s) -
HAWKES H. A.
Publication year - 1959
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1959.tb02549.x
Subject(s) - biology , sewage , ecology , flushing , fauna , ecological niche , population , nozzle , nuisance , environmental science , environmental engineering , habitat , physics , demography , sociology , endocrinology , thermodynamics
Two difficulties in treating sewage in bacteria beds—namely, the choking of the beds by excessive growths of micro‐organisms and the nuisance from flies breeding in the beds—are considered as one ecological problem. The effect of the manner in which the sewage is applied to the bed through different types of distributor nozzle on the film and fauna populations was studied. It was found that nozzles which provided a strong flushing action on the surface did not prevent excessive growth of film below the surface but did limit the grazing fauna, as a result of which the amount of film was greater than under jets in which the flushing action was reduced. Where this reduction was effected by allowing the sewage jet to first impinge on a splash plate, uniform conditions were produced in the medium below, where the species were in direct competition for food in the one ecological niche. As a result the fly larvae ( Anisopus fenestralis and Psychoda sp.) suppressed the population of Achorutes subviaticus (Collembola) during the winter. Where the flushing action was reduced by allowing the sewage to flow through an increased number of holes of smaller bore, two niches were provided, one wet region, subject to some flow of sewage, and the other drier region between the jets. Under this method, two populations existed side by side, Achorutes being present throughout the year in the drier zone and A. fenestralis larvae occupying the sub‐jet zones.