Investigations on the purification of Boston sewage made at the sanitary research laboratory and sewage experiment station of the Massachusetts institute of technology, with a history of the sewage-disposal problem / By C.E.A. Winslow and Earle B. Phelps.

  • Charles-Edward Amory Winslow
Date:
1906
Catalogue details

Licence: In copyright

Credit: Investigations on the purification of Boston sewage made at the sanitary research laboratory and sewage experiment station of the Massachusetts institute of technology, with a history of the sewage-disposal problem / By C.E.A. Winslow and Earle B. Phelps. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    Finally, m connection with the development of this process, should be mentioned Scott-Moncrieff, who carried its principles to a logical extreme in a series of experiments at Ashtead in 1898. He believed that several different types of organisms were concerned in the puri- fying process , and that their separate and successive cultivation under perfect aerobic conditions would give the most favorable results. He therefore constructed a series of nine trays of 1-inch coke, each 2 by 7 feet by 7 mches deep, arranged one over the other, with a space of 2 inches between each pair. The effluent frorn a cultivation tank was discharged on the upper tray by a tipping bucket at a rate of 1.3 million gallons per acre per day (0.14 on the whole area of nine trays), and its passage through the series occupied from eight to ten mmutes. The degree of purification attained, as indicated in Table XLII, was extraordinarily high. Table XLll.—Results of trickling jUiraiion through Scott-Moncrieff's trays {Scott-Moncrief, [Parts per million.] EflBuents of- Cultivation tank First tray Second tray Third tray Fourth tray Fifth tray Sixth tray Seventh tray Eighth tray Ninth tray Nitrogen as- Free am- monia. 103 86.5 74.2 41.2 33 12.4 14.4 2.9 1.7 2.1 Albumi- noid am- monia. 12.3 10.3 8.2 4.9 2.9 1.2 2.9 2.5 5.3 4.9 Nitrites. 0 9.9 9 7.8 6.6 4.8 5.1 0 0 Slight tr. Nitrates. 1.2 1 4.8 18.7 27.6 46.8 44.2 66 73.2 90 Oxygen consumed in 4 hours at 80° F. 98.4 66.9 57.7 44.9 17.3 12.8 15 7.6 4 5.9 A plant of this type has been installed at Caterham Barracks, where it handles daily 16,000 gallons of very strong sewage at a rate of 0.4. Oxygen consumed is reduced from 92 to 27 parts per million, free ammonia from 149 to 50 parts, and organic nitrogen from 27 to 7 parts, with a formation of 90 parts of nitric nitrogen (Kideal, 1901). The German commission on its visit to England in 1902 reported that the effluent from this plant was stable, although it contained 68 parts per million of nitrogen as free ammonia, 5.8 parts of organic nitrogen, and 51 parts of oxygen consumed (Bredt- schneider and Thumm, 1904). It is not clear that there is any such complex division of labor between various classes of nitrifiers as Scott-Moncrieff postulates. Whether any important advantage is to be gained by dividing a trickling filter into layers with air spaces between has never been definitely determined. At Salford Corbett found no gain from divid- ing his filters into three or four successive heights of 20 inches each (Rideal, 1901).