The experimental bacterial treatment of London sewage : being an account of the experiments carried out by the London County Council between the years 1892 and 1903 / by Frank Clowes and A.C. Houston.

  • London County Council
Date:
1904]
Catalogue details

Licence: In copyright

Credit: The experimental bacterial treatment of London sewage : being an account of the experiments carried out by the London County Council between the years 1892 and 1903 / by Frank Clowes and A.C. Houston. Source: Wellcome Collection.

    31/356 (page 11)
    The method of workihg the beds was as follows:— The two coarse primary beds- were filled with crude sewage simultaneously and as quickly as possible to a level with the top of the solid material; the beds were allowed to remain full for two hours, and were then drained into the tine secondary beds. These remained full for two hours, and were then drained off. The effluent from the. coarse primary Kentish ragstone-bed was always discharged into the'tine secondary Kentish ragstone-bed, and that from the coarse coke-bed into the tine coke-bed. During the outflow of the effluent from each bed samples were taken every few minutes. These samples were mixed, and the average liquid thus obtained was subjected to analysis. The crude sewage with which the primary beds were filled was sampled and examined in a similar manner. The following table gives particulars as to the number of times the coarse beds were filled, and as to the quantity of crude sewage dealt with by them. Table III. Date. Number of days. Number of tU}son which each bed was filled. Number of fillings of each bed per day. Average quantity of crude sewage dealt * ith by each bed per day. Expressed in terms of an acre. During the whole period. During the days on which the beds were working. Coke- bed. Rag stone- bed. Coke- bed. Ragstone- bed. 1898 1899 Gallons. Gallons. Gallons. Gallons. 22 Sept, to 9 Jan. ... 110 83 1 519,750 415,800 688,825 551,060 1899 11 Jan. to 15 April ... 95 73 2 626,576 601,128 815,407 782,290 The capacity of the two coarse beds was estimated at various times with the following results:— Table IV. Capacity of the Capacity of the b»*d stated as a ]K*rcentage of the volume < f the empty tank. Corresponding capacity per acre of bed. Average weekly percentage reduction in the capacity of the coke- rugstone- bed. bed. Coke- Ragstone- bed. bed. Coke- Ragstone bed. j bed. coke- j rugstono- bed. bed. Gallons. Oallo'iH. 29 Sept., 1898 ... 250 200 50-0 40-0 680.625 544,500 11 Jan., 1899 ... 195 183 390 530,887 498,217 0-73 9 Mar., 1899 168 174 336 34 8 457,380 478,715 0-68 The “original capacity” (September 29) was taken about 10 days after the experiments had been started ; it is probably below the total capacity, since it was taken while the beds were being emptied, and the drainings of the beds were therefore not included. No doubt a more trustworthy method of estimating capacity consists in filling the bed after it has drained for a definite time, which should be the same in all processes of taking capacities, it might be well that a standard I