Disposal and purification of factory wastes or manufacturing sewage / by H. W. Clark.

Date:
1910
Catalogue details

Licence: In copyright

Credit: Disposal and purification of factory wastes or manufacturing sewage / by H. W. Clark. 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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    Raw Waste. [Parts per 100,000.] Unfiltered. Filtered. Ammonia. ALBUMINOID. Oxygen Con- Total. Loss on Ignition. Fixed. Total. Loss on Ignition. Fixed. Free. Total. In Solution. sumed. 150.0 60.0 90.0 108.0 30.2 77.8 .58 .80 .30 8.14 Settled Waste. 94.1 26.9 67.2 - - - .48 .31 3.61 Two filters, Nos. 380 and 381, were put into operation, receiving the supernatant waste after sedimentation. No. 380 was a trickling filter constructed of 6 feet in depth of broken stone, and No. 381 was con- structed of 3V2 feet in depth of sand with an effective size of 0.26 milli- meter. The trickling filter (No. 380) was operated for seven weeks at rates varying from 500,000 to 750,000 gallons per acre daily. Its effluent was found to differ little in appearance and analysis from the applied waste. Filter No. 381 was first operated at a rate of 50,000 gallons per acre daily; then, after a few weeks, at a rate of 150,000 gallons per acre daily with the effluent from Filter No. 384. (See below.) Operated in this way, Filter No. 381 gave an effluent which was always clear and odorless, but more or less colored by the blue dye in the applied waste. A large part of the organic matter applied was removed by the filter, as is shown by the following average analysis of its effluent: — Average Analysis of Effluent from Filter No. 381. [Parts per 100,000.] Ammonia. Nitrogen as — Oxygen Consumed. Free. Albuminoid. Nitrates. Nitrites. .3839 .0703 .37 .0092 1.29 Filter No. 384 contained 2 feet in depth of sand and was operated at a rate of 1,500,000 gallons per acre daily. After three weeks’ operation the upper sand in the filter became badly clogged; 3 inches of sand were removed and a few days later the rate was reduced to 1,000,000 gallons
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