Water and Water Supply

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D. Van Nostrand, 1875 - 145 páginas
 

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Página 120 - ... we are led, in each case, to the inevitable conclusion that the oxidation of the organic matter in sewage proceeds with extreme slowness, even when the sewage is mixed with a large volume of unpolluted water, and that it is impossible to say how far such water must flow before the sewage matter becomes thoroughly oxidised.
Página 119 - Thus, whether we examine the organic pollution of a river at different points of its flow, or the rate of disappearance of the organic matter of sewage when the latter is mixed with fresh water and violently agitated in contact with air, or finally the rate at which dissolved oxygen disappears in water polluted with 5 per cent, of sewage, we are led in each case to the inevitable conclusion that the oxidation of the organic matter in sewage...
Página 105 - Clay puddle will only resist the pressure of water when it rests solidly 104 on an even bed, so as to prevent the -water forcing holes through it, which -will be the case if there is a rough uneven surface and open space beneath." {Suggestions as to the preparation of plans as to Main /Sewerage and Drainage and as to Water Supply...
Página 122 - ... produce an injurious effect upon health. Therefore, if a large proportion of organic matter was removed by the process of oxidation, the quantity left might be quite sufficient to be injurious to health. With regard to the oxidation, we know that to destroy organic matter the most powerful oxidizing agents are required ; we must boil it with nitric acid and chloric acid and the most perfect chemical agents. To think to get rid of organic matter by exposure to the air for a short time is absurd.
Página 120 - ... per cent of sewage, we are led, in each case, to the inevitable conclusion that the oxidation of the organic matter in sewage proceeds with extreme slowness, even when the sewage is mixed with a large volume of unpolluted water...
Página 40 - ... about the amount of available water, and about the way to get it. We are told that in chalk countries the rivers and streams carry off at once about, a fifth of the rain-fall ; that the evaporation and absorption by vegetables and animals amounts to as much as a third, and that, the remainder (ie...
Página 119 - ... dissolved oxygen being well known to be chemically much more active than the gaseous oxygen of the air." It was found, however, that the action of this dissolved oxygen was not really anything like so quick or so perfect as generally supposed, and that 62 per cent.
Página 121 - I believe that an infinitesimally small quantity of decayed matter is able to produce an injurious effect upon health. Therefore, if a large proportion of organic matter was removed by the process of oxidation, the quantity left might be quite sufficient to be injurious to health. With regard to the oxidation, we know that to destroy organic...
Página 117 - There is no process practicable on a large scale by which that noxious material (sewage matter) can be removed from water once so contaminated, and therefore I am of opinion that water which has been once contaminated by sewage or manure matter is henceforth unsuitable for domestic use.
Página 101 - ... it was charged with mud, and though large cisterns were provided, in which, by an ingenious arrangement, much of the sediment was caught, still it was not considered satisfactory by Frontinus, who was the engineer and who, therefore, under his patron the Emperor Nerva, altered the source. Still the water that came to Rome required to have settling tanks, as described by Mr. Parker in a paper I quoted before, and from which I again quote. " The building consisted of four chambers — two beneath...

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