Works of sewage disposal : with some historical notes on problems arising in connection with the treatment of effluents from the textile industries, 1870-1931.

  • Bradford
Date:
1931
Catalogue details

Licence: In copyright

Credit: Works of sewage disposal : with some historical notes on problems arising in connection with the treatment of effluents from the textile industries, 1870-1931. Source: Wellcome Collection.

    24/120 page 6
    Lanoline. At one stage of the commercial development of the borough it paid the woolcomber to extract part of the fat from his effuent, but as the quantity of wool The Trouble of dealt = With incressedam tne = piiccm omer ine Wool Fat. residual fat or grease declined, and eventually nearly all the effluent was passed entirely untreated into the sewers, and the sewage works became inadequate to deal with the difficulty. The esti- mated quantity of this grease thus poured into the Beck was, in 1889, stated at twenty-five tons a day when the wool trade was suffering a bad time, and fifty tons a day or more in prosperous times. In addition, of course, vast quantities of soap and alkali were used in its removal from the wool. Lanoline fat is of a very peculiar nature. During the period when the late Alderman Robert Pratt was Chairman of the Sewage Committee, a great deal of work was done to reach an understanding of the problem which had to be dealt with. Elaborate analyses of the sewage were made by Mr. F. W. Richardson, F.I.C., the Borough Analyst, and following upon these analyses, the properties of lanoline were carefully investigated by Professor Dewar (later Sit John Dewar). At the request of the Corporation, Pro- fessor Dewar made experiments which resulted in his discovering that the lanoline fat, being of very nearly the same specific gravity as water, would not rise to the surface as ordinary fats might do, and could not be skimmed off. It remained in sus- pension in extremely minute globules. Professor Dewar found further that it had a peculiar property of adhesiveness to water, as he called) it, whichstetarded the exttactiom Or stem ater from the sewage sludge, so that even after prolonged precipita- tion the sludge contained 98 per cent. of water as compared with go per cent. in the sludge of ordinary town sewage. This state of dilution increased five times the amount of sludge to be dealt with, and made the production of a satisfactory sludge- cake very difficult. One more difficulty arose from the presence in Bradford of many dyeworks, which also poured their effluents into the sewers, so that the sewage at one time ran acid, and at another strongly alkaline. After many experiments the method adopted was to precipitate the solids with lime and the effluent then underwent a final purification by filtration through coke-breeze. The works were 6]
    digitised image 1
    digitised image 2
    digitised image 3