Partial Report Upon the Comprehensive Plan for the Collection, Purification and Disposal of the Sewage of the Entire City; Report of the Bureau of Sur (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 edition. Excerpt: ...way 8 pounds of bleach per bed were put upon the three pooled filters (20-3, 5 and 6) on January 17th and all the filters rested until January 20th. During the rest the bleach changed the appearance and consistency of the clogging matter; its color was a dirty yellow and from a sticky, tenacious mat it had become granular, and was capable of being easily removed from the media by hand. Analysis of the deposit in 20-6 shown below, prior and subsequent to bleach treatment, does not show much change except an increase in fats, which accumulated between the dates of examination. The storage of solids, and especially of fats, between January 3d and 21st is shown by the content in grams of one liter of the deposit as follows: The surface jelly had been disintegrated, but the force of the ordinary spray was not sufficient to wash it through; so on Sunday, January 23, 1910, the dosing mechanism was not used, and the nozzles discharged continuously for three hours, the head being changed from time to time by hand in order to cover the entire area. The influent did not appear to contain more than 20 parts per million suspended solids and the effluent was but slightly dirtier. The spray, therefore, did not have sufficient force to dislodge the clogging matters. It seemed that considerable force would be required to dislodge the accumulated solids in the voids of the filters, as all gentle treatments had failed to eliminate pooling on 20-1, 5, and 6. On January 24th, therefore, after three and a half hours' rest, filter No. 20-5 was washed with water under pressure from the fire hydrant, applied through a one-inch fire nozzle, held vertically a few inches above the stones. The rate of discharge was 77 gallons per minute and was applied twice; the...