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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    nitrification became fairly constant in the filter, the odor of the effluent became much less marked, and with the advent of colder weather it was distinctly less noticeable; and during 1899 the effluent was clear, prac- tically colorless and without a distinguishing odor. At the end of 1898 the rate of operation of the filter was reduced to 50,000 gallons per acre daily. The average analysis of the liquor applied to and of the effluent from the filter during the last three weeks of Decem- ber, 1898, and the first week of January, 1899, was as follows: — [Parts per 100,000.] Ammonia. Nitrogen as — Oxygen Con- sumed. Bacteria per Cubic Centimeter. Free. Albumi- noid. Nitrates. Nitrites. Applied liquor, Effluent .10 .80 2.2500 0.0750 2.70 .0500 9.15 0.38 77,000 On Jan. 7, 1899, the strength of the applied liquor was practically doubled, but the rate of application was reduced to 25,000 gallons per acre daily. The average analysis of the applied liquor during this period was about the same as that of the sample obtained from the creamery previously mentioned. The filter (No. 106) was continued in operation up to the end of November, 1899. Beginning in June, water at the boiling point was mixed with the milk, and it was still at about 100° F. when applied to the filter. This method was pursued because, at the creameries, the cans, churns, etc., were washed with boiling water. It was desired to ascertain not only what effect this treatment of the milk as washed from the utensils would have upon its purification by the bacteria in the filter, but also the effect of high temperatures upon the surface of the filter. Upon July 10 salt was added to the creamery waste applied to the filter thereby increasing the chlorine present to over 500 parts. This was done because considerable ice cream was made at the creamery during the summer months, and, consequently, the waste contained a large amount of salt. Nitrification with in the filter was not seriously disturbed by any of these changes, however, although the amount of free and albuminoid ammonia in the effluent increased slightly. The filter continued to purify the waste successfully, as is shown by the following table, which gives the average analysis of the liquor applied to and of the effluent from the filter during the latter part of 1899: —
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