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The Bacterial Purification of Gasworks' Liquors. The Action of the Liquors on the Bacterial Flora of Sewage
- Frank Charles Happold, Arthur Key
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- Journal:
- Journal of Hygiene / Volume 32 / Issue 4 / October 1932
- Published online by Cambridge University Press:
- 15 May 2009, pp. 573-580
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A study has been made of the bacterial flora in the sewage supplied to, and the effluent from, the bacteria beds which deal with the liquors produced at the Coventry gasworks. A high count in the effluent from the beds of bacteria containing an oxidase system, or a relatively large increase in the viability of such organisms when compared with the original sewage, has been found to be concurrent with good purification in the beds, and vice versa.
The bacterial flora undergoes considerable modification in the beds, and also when mixed with 4 per cent, of its volume of spent liquor in the laboratory. The total viable count of the treated sewage is reduced under these conditions, but the count of those bacteria which give the direct oxidase reaction and therefore catalyse the oxidation of catechol is relatively increased.
A gram negative vibrio (strain 0 1) is the only bacterium isolated which has proved capable of breaking down monohydric phenols. It has been constantly isolated from the effluent liquors.
Gasworks' ammonia liquor in the relatively high concentrations used exerts a markedly toxic action on all types of sewage bacteria, and the purification of this liquor by the beds is not so satisfactory. The toxicity is probably caused by the highly alkaline reaction of the liquor.
This investigation was commenced by one of us (F. C. H.) in conjunction with Dr Allan C. Monkhouse, who was at the time Research Chemist to the Liquor Effluents Sub-Committee of the Institution of Gas Engineers. Dr Monkhouse accepted another appointment shortly after the commencement of the work, and was therefore unable to assist further, but we should like to express our indebtedness to him during the initial period. We are also indebted to Prof. J. W. McLeod and Prof. J. W. Cobb for their kindly interest and encouragement, and to Mr P. N. Langford, Engineer and Manager of the Coventry Gas Department, for the facilities he so generously placed at our disposal at Coventry.
One of us (F. C. H.)is in receipt of grants from the Medical Research Council, and would again express his thanks to that body.
One of us (A. K.) is indebted to the Liquor Effluents and Ammonia Sub-Committee of the Institution of Gas Engineers for permission to publish this work.
Diet, nutrition and the prevention of cancer
- Timothy J Key, Arthur Schatzkin, Walter C Willett, Naomi E Allen, Elizabeth A Spencer, Ruth C Travis
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- Journal:
- Public Health Nutrition / Volume 7 / Issue 1a / February 2004
- Published online by Cambridge University Press:
- 02 January 2007, pp. 187-200
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Objective:
To assess the epidemiological evidence on diet and cancer and make public health recommendations.
Design:Review of published studies, concentrating on recent systematic reviews, meta-analyses and large prospective studies.
Conclusions and recommendations:Overweight/obesity increases the risk for cancers of the oesophagus (adenocarcinoma), colorectum, breast (postmenopausal), endometrium and kidney; body weight should be maintained in the body mass index range of 18.5–25?kg/m2, and weight gain in adulthood avoided. Alcohol causes cancers of the oral cavity, pharynx, oesophagus and liver, and a small increase in the risk for breast cancer; if consumed, alcohol intake should not exceed 2?units/d. Aflatoxin in foods causes liver cancer, although its importance in the absence of hepatitis virus infections is not clear; exposure to aflatoxin in foods should be minimised. Chinese-style salted fish increases the risk for nasopharyngeal cancer, particularly if eaten during childhood, and should be eaten only in moderation. Fruits and vegetables probably reduce the risk for cancers of the oral cavity, oesophagus, stomach and colorectum, and diets should include at least 400?g/d of total fruits and vegetables. Preserved meat and red meat probably increase the risk for colorectal cancer; if eaten, consumption of these foods should be moderate. Salt preserved foods and high salt intake probably increase the risk for stomach cancer; overall consumption of salt preserved foods and salt should be moderate. Very hot drinks and foods probably increase the risk for cancers of the oral cavity, pharynx and oesophagus; drinks and foods should not be consumed when they are scalding hot. Physical activity, the main determinant of energy expenditure, reduces the risk for colorectal cancer and probably reduces the risk for breast cancer; regular physical activity should be taken.