Investigations on the purification of Boston sewage made at the sanitary research laboratory and sewage experiment station of the Massachusetts institute of technology, with a history of the sewage-disposal problem / By C.E.A. Winslow and Earle B. Phelps.
- Charles-Edward Amory Winslow
- Date:
- 1906
Licence: In copyright
Credit: Investigations on the purification of Boston sewage made at the sanitary research laboratory and sewage experiment station of the Massachusetts institute of technology, with a history of the sewage-disposal problem / By C.E.A. Winslow and Earle B. Phelps. 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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![local conditions. In many regions the cost of constructing sand filters of siifricient area to treat sewage at a rate of 0.1 niillio.n gal- lons per acre per day would be entirely prohibitive. For England, m particular, it was necessary to modify the process so as to obtain liigher rates of filtration, even at the cost of a lower purificatioj . This was first accomplished in a practically effective manner in a series of experiments carried out at Barlmig for the London county council, the attainment of a liigh rate being made possible by the use of materials coarser than sand. Almost insensibly tliis changed the whole conception of sewage purification. With coarse material there was little true filtration, and it became evident that the bed was really not a filter, but an oxidizing macliine. Frictional resistance could no longer be depended on to delay the flow tlxrough the bed sufficiently to allow purification tg occur. It was neces- sary, therefore, to regulate the rate by constructing water-tight fil- ters, in wliich the sewage could be retained in contact with the filling material and its accumulated growth of micro-organisms. Hence tliis type of purifying plant was called the contact bed. It operated with success, attracted wide attention, and inspired the design of numerous so-called biological filters on similar principles. W. J. Dibdin, chemist to the London county council, was one of the first English sanitarians to grasp the essential princij^les of sew- age purification. In studies of the self-purification of the Thames, H. C. Sorby had pointed out as early as 1883 the part played by living organisms, although he had in view cluefly the consumption of solids by the larger microscopic forms. In 1884 Dupre went a step fiu-ther in affirming the relation of organic life to the oxida- tions which take place in a purifying stream. Didbin, who had been associated mth both these observers, read a paper before the Institution of Civil Engineers in 1887, in which he worked out the whole theory as follows: In all probability the trae way of purifying sewage, where suitable land is unavailable, will be first to separate the sludge, and then to turn into the effluent a charge of the proper organism, whatever that may be, specially cultivated for the purpose, and retain it for a sufficient period, during which time it should be fully aerated and finally discharged into the stream in a really purified condition. This, indeed, is only what is aimed at and imperfectly accomplished on a sewage farm. [Dibdin, 1903.] The treatment of London sewage by chemical precipitation alone was recognized by the metropohtan sewage commission in 1884 as only a temporary expedient, a final treatment on land being con- templated. As soon, therefore, as the Massachusetts results^ were published Dibdin saw their importance and began a series of inves- tigations on the treatment of sewage on the Lawrence principle, but at more rapid rates. His first series of investigations was carried on between May and August, 1892, to determine the best material](https://iiif.wellcomecollection.org/image/b21358205_0060.jp2/full/800%2C/0/default.jpg)
