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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    Average Analysis of Effluent from Filter No. 332. [Parts per 100,000.] Color. Ammonia. Nitrogen as — Oxygen Con- sumed. Arsenic. Hardness. Free. Albumi- noid. Nitrates. Nitrites. .17 2.2524 .0735 2.31 .5722 .51 .03 18.5 Average Analysis of Effluent from Filter No. 333. .11 | 3.6720 .0760 0.96 .0778 .45 .01 15.0 Average Analysis of Effluent from Filter No. 334. 2.5781 1.5631 0.08 .0478 8.58 .06 24.7 Average Analysis of Effluent from Filter No. 333. [Parts per 100,000.] Color. Ammonia. Chlorine. Nitrogen as — Oxygen Con- sumed. Arsenic. Hard- ness. Free. Albumi- noid. Nitrates. Nitrites. Applied. Effluent. .10 .2841 .0371 11.30 5.59 .0014 .26 .33 .02 -0.2 From the above experiments it seemed probable that good sand filters receiving the sewage from the outlet of the settling tanks at the tannery would, if operated at reasonable rates, produce good nitrification even with considerable arsenic in this waste, but that some arsenic would accumulate in the upper layers of the sand; that it would be best to pass the sewage, after sedimentation, through filters of coke breeze for partial purification and for the removal of a considerable percentage of arsenic before passing the sewage to sand filters. During 1909 filters were again operated with waste from this tannery. The first filter, containing 3% feet in depth of sand, was operated at rates varying from 50,000 to 150,000 gallons per acre daily, producing an effluent which was odorless and but slightly turbid. A Trickling Filter receiving Tannery Sewage. — A second filter, containing 6 feet in depth of broken stone, was started in May, 1909, and was operated at rates varying from 500,000 to 1,500,000 gallons per acre daily, and a well-nitrified, stable and practically odorless effluent resulted. The supernatant liquor after a short period of standing was