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- Hanaeus, Jörgen
(författare)
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Swedish field experiences woth chemical precipation in stabilization ponds
- 1984
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Ingår i: Cold regions engineering. - : Canadian Society for Civil Engineering. - 919305601 ; , s. 547-564
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Konferensbidrag (refereegranskat)abstract
- Swedish sewage treatment plant history shows a development towards compact plants. For smaller communities with big changes in flow and temperature, the compact plants offer several problems. Yearly studies of chemical precipitation in stabilization ponds have demonstrated an overall reduction of organic matter (as COD) with about 75% to a level of somewhat below 100 mg O//2/1, and a reduction of total phosphorus with 90% to a level of about 0. 7 mg P/1. These values were reached under ordinary operation of the plants and no optimization efforts have been made. All wastewater have been treated (no over-flows). Two tracer studies (Rhodamine B) have demonstrated the appearance of strong short-circuiting flows in ponds systems and the inserting of simple walls is recommended to avoid an at least hygienic risk. Sludge collection in ponds can be carried out by a dredger or by emtying the pond and using an excavator. Both ways have been successfully tried in full scale in Sweden.
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