London's Pulse: Medical Officer of Health reports 1848-1972
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Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
London County Council 1900
[Report of the Medical Officer of Health for London County Council]
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Table 2. Particulars as to the working of the Bacteria Beds.
| No. | Name of town or district. | Time during which the beds were in use. | Name or number of the bed used. | Character of the liquid supplied to the beds. | Particulars of the settling and of the detritus tanks. | Chemicals used for treating the sewage previous to bacterial treatment. | Number of hours | Average percentage purification effected on the crude sewage, as measured by the relative quantities of | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Occupied in fillings the beds. | During which the beds remained full (contact period). | Occupied in emptying the beds. | During which the beds remained empty (aeration period). | Number of filings per 24 hour?. | Number of contacts in successive beds. | Quantity of sewage treated in 24 hours, per acre of bed, one foot deep. Calculated for the purpose of comparison | Oxygen absorbed by the crude sewage and by the final bacteria bed effluent. | Albuminoid ammonia present in the crude sewage and in the final bacteria bed effluent. | ||||||||||||
| Capacity. | Length. | Bate of flow of sewage through the tanks. | Name of chemical. | Grains per gallon of sewage. | ||||||||||||||||
| Average percentage purification. | Number of hours occupied in absorption. | Temperature at which absorption took place ???. | ||||||||||||||||||
| Gallons. | Feet. | Gallons per day. | Gallons. | |||||||||||||||||
| 1 | Accrington | Aug., 1899 to date | Sewage which has passed through a detritus chamber provided with a fixed screen, and which has afterwards passed through two sets of septic tanks, each set consisting of three tanks. The sewage is distributed on the beds by means of sprinklers | All the detritus and sand is left either in the detritus chamber or two first septic tanks. Storm water is separate | Continuously worked | l | 215,111 | 90.0 | 4 | 70 | 91.3 | |||||||||
| 2 | Aldershot | Crude sewage after having passed through a small detritus chamber. No screening. Storm water is separate from sewage | Nil | 2½ | 2 | Primary beds deal with about 500,000 gallons per day | 91.0 | 4 | 80 | 90.6 | ||||||||||
| Second ary be ds wor ked on conti nuous flow pr inciple | Secondary beds deal with about 130,000 gallons per day | |||||||||||||||||||
| 3 | Acfcon | Contin uous m ethod | About 372,300 | |||||||||||||||||
| ^ Wintt aker a nd Bry ant spr inklers are use d) | ||||||||||||||||||||
| 4 | Aylesbury | Sewage which has previously passed through a settling tank | 40,000 | 50 x 30 | 250,000 | Varies according to flow from the town | 2 | ½ and 1 | 2 | A minimum quantity of 250,000 gallons to the six coke breeze beds (about ½ acre) per day | (60 to 80 per cent. purification is effected.) | |||||||||
| 5 | Barnsley | During the last 12 months | 1, 2 and 3 | Only night water which has previously passed through a septic tank is treated, not sewage. Road detritus and sand are separated from the liquid | 200,000 | 90 x 120 | 200,000 (about)' | Lime Alumino ferric | Depends upon the night flow and weather | 1 | 1 | |||||||||
| 6 | Birmingham | Less than six months | Storm water and excess sewage from Reamain sewer | 5,441,875 | 315 (average) | 22,000,000 | None | ... | 2 | 7 | 3 | 12 | 1 | 1 | Varies | 53.5 | 4 | 80 | ||
| 7 | Blackburn | 2 years | Screened sewage which has been from 12 to 16 hours in the septic tank | None | V aried during the experiments | 2 and 3 | 2 | 75 to 80 | 4 | 80 | 971 | |||||||||
| 8 | Bloxwich district of Walsall | Sewage which has passed through a septic tank | 1 | 2 | 1 | 3 | 2½ | 2 | 96.3 | 4 | 97.7 | |||||||||
| 9 | Bristol— | • •• | Continuous process | ... | 1 | 1,048,666 | 92 | 4 | 80 | 94 | ||||||||||
| At Knowle | Two years | ... | Sewage which has passed through a septic tank | ... | ... | ... | 1 | 204,893 | 71 | 4 | 80 | 93 | ||||||||
| At St. John's-lane | Two years | ... | Do. do. | ' | ||||||||||||||||