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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    65 Effluent from Sand Filter No. 368. [Parts per 100,009.] Color. Ammonia. Nitrogen as — Oxygen Consumed. Bacteria per. Cubic Centimeter. Free. Albuminoid. Nitrates. Nitrites. .36 12.83 0.27 5.25 .4896 0.86 5,000 Effluent from Trickling Filter No. 370. .50 6.96 0.66 5.26 .0498 3.15 502,000 Paint Mill Wastes. Investigations in regard to wastes from a paint factory were made during 1902, 1903 and 1904 as the result of an application in November, 1902, from a local board of health, in which it was stated that much com- plaint had been made to them concerning the contamination of a lake and connecting brooks by the wastes from certain paint mills. The lake was not a source of water supply, but ice was cut from it in winter and in summer it was used by the students of a girls’ college for boating and bathing, the boat-house, bath-house and swimming-float being about 250 yards from the outlet of the brook into the lake. These wastes caused the brook to be badly colored oftentimes. The lake, too, became colored to some extent, and with the wastes a large amount of lead was carried into these waters. Mineral paint, so called, was made, chrome iron ore being the basis. This was mixed with lime or sodium carbonate, or both, and heated, and the sodium chromate formed was passed into solution. This material was then treated in large tanks with lead acetate and sodium bichromate, lead chromate being precipitated, and this yellow body formed the main portion of the paint shipped from the works. Sulphuric acid was added to the tanks at times to vary the shade of yellow formed. « Lead acetate was made at the plant by allowing acetic acid to pass over lead. Blue paint was made by treating the lead chromate with Prussian blue, and green paint by mixing the yellow and the blue. A red paint was also made of the lead chromate by treating it with aniline dyes. The only acids said to be used around the works were acetic, nitric and sulphuric. Neither arsenic nor mercury was used. The lead chromate, after being precipitated, was pressed in filter presses and then mixed or ground with oil. No oils were supposed to be allowed to run to waste from the grind- ing room. Kerosene was used, however, to prevent scale in the boilers, and the exhaust contained some oil which was blown off into the brook.