Specification of Dugald Campbell : treating sewage, &c.

  • Campbell, Dugald.
Date:
1872
Catalogue details

Licence: Public Domain Mark

Credit: Specification of Dugald Campbell : treating sewage, &c. Source: Wellcome Collection.

    7/10 (page 5)
    Campbell's Improved Frocess for Treating Seivage, 8fc. of sewage and solution of acid phosphate of lime, and the whole will then he well mingled by running together until the mixture reaches the reservoir, and then no use of agitators will he required in the reservoirs. After the liquid is run off from the precipitate, the pre- 5 cipitate is collected and may he used in its then existing state as a manure, or it may be collected and a small quantity of acid, preferably sulphuric acid, may he added to it, and it may be dried by any of the well-known methods employed for drying precipitates from sewage or such like substances, and in this state it may be used or sold as 10 a manure. As sewage differs very much in quality, so will the quantities of solution of acid phosphate of lime required to be added to the sewage differ; a strong sewage, that is a sewage containing a large quantity of fecal matter either in solution or suspension, or both, requiring more 15 than a weak sewage; generally I have found that from about one and a half parts to two and a half parts by weight of the acid phosphate of lime to every one thousand parts by weight of raw sewage of an average kind to answer well; a very strong sewage would require a little more of the acid phosphate and a very weak sewage would 20 require a little less. The quantity of hydrate of lime or hydrate of magnesia and lime to be added to the sewage (preferably in the form of a milk or cream) is as near as may be about half the weight of the acid phosphate of lime that is added to the sewage. Having thus described my Invention, and the means which I adopt 25 in carrying out the same into effect, I would have it understood that what I claim is, the employment of artificial or manufactured phosphates of lime in the treatment of sewage and in the production of manures therefrom, substantially as described. In witness whereof, I, the said Dugald Campbell, have hereunto 30 set my hand and seal, this Twenty-sixth day of September, in the year of our Lord One thousand eight hundred and seventy- two. DUGALD CAMPBELL, (l.s.) LONDON: Printed by George Edward Eyre and William Spottiswoode, Printers to the Queen’s most Excellent Majesty. 1872.