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.

    51/356 (page 31)
    The filling of each bed occupied about half an hour; the bed remained full for two hours and occupied one hour in emptying. The resting period varied with the number of fillings per 24 hours. The crude sewage samples for analysis were taken at the inlet to the tank, and the settled sewage samples were taken at the outlet. The arrangement of the tanks is shown in the diagram on page 22. It should, however, be borne in mind that the bottom of Tank 0 was on the same level as the top of Tanks A and B. At first both the beds were filled with settled sewage four times a day, but about the middle of January, 1901, No. 1 bed was worked on the continuous supply principle for one week, and then both the beds were thrown out of work until April the 15th, 1901. This rest was necessitated at first on account of lime water from the chemical treatment of the sewage at this Outfall having gained access to the beds, and afterwards by the choking of the suction pipe of the pump supplying the settling tank with the crude sewage. Owing to a change in the pumping arrangements which was made in March, 1901, it was impossible to give the settling tank a continuous supply of sewage, and it was also impossible to always fill the beds four times each day. The other days during the specified period, on which the coke-beds were not filled, were either Sundays, when they never were in use; Saturdays, when the height of the sewage in the main was not sufficient during the morning to work the pump ; public holidays and the first week in August, which latter was fixed as the time for the annual holiday of the coke-bed samplers. The original capacity of the wet coke-beds was not estimated, since in the case of both beds the coke had been previously in use, but after the experiments of Series II. had been discontinued for about 10 weeks and the coke had been reduced in depth from ] 3 to 6 feet, the capacity of the bed was measured and found to be 2,900 gallons, or 32-2 per cent, of the total capacity of that portion of the tank (measured when empty) which contained the coke-bed. 'The following table indicates the results of the measurements of the capacity of the beds made at various times.