ISSN:
1745-6584
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Energietechnik
,
Geologie und Paläontologie
Notizen:
The function of a septic tank-soil absorption system is to purify the wastewater discharged from the home before reaching the ground water. However, failure often occurs in the soil absorption field. Failure can originate from two causes: (1) inadequate infiltration of effluent into the soil, due to soil clogging or an increase in loading which results in surfacing septic tank effluent, and (2) inadequate purification in the soil during percolation because of short travel times which can be due to presence of very permeable, shallow soils or to local overloading. Inadequate purification may result in pathogenic pollution of private well-water supplies.Failures of the second type can be prevented through proper design and operation of the soil absorption field. Studies have shown that 3 feet (90 cm) of unsaturated soil are adequate in purifying septic tank wastes with the exception of nitrogen removal. However, 4-inch (10 cm) diameter perforated drain pipe commonly used for distribution leads to local overloading near the point of inlet whereas other areas in the seepage system do not receive effluent at all. This leads to locally high flow rates of the waste through the soil reducing the soil's efficiency for pathogenic organism removal. Uniform distribution of the septic tank effluent over the entire soil absorption field is necessary to relieve this situation.One method by which uniform distribution can be achieved over a large area is through a pressurized system. By properly sizing the diameters of the pipes and the number and diameter of the orifices in the distribution laterals, the head losses across the orifices will be great enough to cause the entire network to fill before the liquid is applied to the soil. This system combines the advantages of dosing with uniform distribution.Three systems have been tested under laboratory and field conditions. The network is easy to manufacture and can be quickly sized. The design guidelines and results of laboratory and field testing are discussed.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1745-6584.1974.tb03051.x
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