Sewage disposal . st1 8, 2d Westborough. 282,000 i 2 20 * Templeton Syst em. In Figures 24 and 25 are shown a general view and certaindetails of the screen chamber at Washington, Pa., which, for-tunately, could be placed near the surface of the ground sothat the screenings can be readily removed by means of a rake,placed in wheelbarrows and hauled to the area chosen for finaldisposal. In planning a screening plant it is most essential to provide insome way for the prompt and effective disposal of the screenings;for it must be remembered that they are composed to a consid- 84 SCREENING AND STRA
Sewage disposal . st1 8, 2d Westborough. 282,000 i 2 20 * Templeton Syst em. In Figures 24 and 25 are shown a general view and certaindetails of the screen chamber at Washington, Pa., which, for-tunately, could be placed near the surface of the ground sothat the screenings can be readily removed by means of a rake,placed in wheelbarrows and hauled to the area chosen for finaldisposal. In planning a screening plant it is most essential to provide insome way for the prompt and effective disposal of the screenings;for it must be remembered that they are composed to a consid- 84 SCREENING AND STRAINING OF SEWAGE erable extent (depending on composition and length of travel ofsewage) of solid fecal matter and their decomposition is of ahighly offensive nature. Efficiency of Coarse Screens. On account of the practicaldifficulties incidental to collecting truly representative samplesof unscreened sewage and to determining, by analytical methods,the exact amount of suspended matter therein, it is difficult to. Fig. 24. View of Screen Chamber at Washington, Pa. discuss the efficiency of screens, in terms of per cent removal,as is done in connection with tanks or niters receiving screenedsewage. Such data as are available generally refer to the amount ofsolid screenings produced, rather than to any comparison ofscreened and unscreened sewage. These data are expressedsometimes in units of weight and sometimes in units of volume,and the relation of these two units is highly variable. Kuichling(1909), in discussing the efficiency of certain mechanical screens,assumes that one cubic foot of wet screenings (83 per cent moist-ure) weighs 30 pounds. Bredtschneider (1905) assumes that acubic foot of wet suspended matter weighs 23 pounds; andMonti found this volume (with 56 per cent moisture) to weigh20 pounds. Considerably higher estimates, based on experience in thiscountry, are given by Johnson (1905), who reports that at theColumbus experiment station, the wet screenings weighed 65
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondo, bookyear1919
