History of the Water Supply of the World: Arranged in a Comprehensive Form from Eminent Authorities, Containing a Description of the Various Methods of Water Supply, Pollution and Purification of Waters, and Sanitary Effects, with Analyses of Potable Waters ...

Portada
Thomson, 1882 - 134 páginas
 

Otras ediciones - Ver todas

Términos y frases comunes

Pasajes populares

Página 7 - ... polluting and inadmissible into any stream : — (a.) Any liquid which has not been subjected to perfect rest in subsidence ponds of sufficient size, for a period of at least six hours, or which, having been so subjected to subsidence, contains in suspension more than one part by weight of dry organic matter in 100,000 parts by weight of the liquid...
Página 7 - ... in suspension more than three parts by weight of dry mineral matter, or one part by weight of dry organic matter in 100,000 parts by weight of the liquid.
Página 17 - ... 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 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...
Página 23 - ... decomposition as the offensive odors observed during the decay will testify, but another portion has been carried off by the stream as soluble nitrogenous organic matter. This nitrogenous matter would be detected a short distance away with greater or less ease according to the volume of water present, and in a stream of large size or in a lake, at no very great distance from the source of contamination, it would be impossible to discover any offensive matter. There is a limit to the delicacy...
Página 37 - That an abundance of water is stored up in the new red sandstone, and may be obtained by sinking shafts and driving tunnels about the level of low water. " That the sandstone is generally very pervious, admitting of deep wells drawing their supply from distances exceeding one mile. " That the permeability of the sandstone is occasionally interfered with by faults or fissures filled with argillaceous matter, sometimes rendering them partially or wholly water tight.
Página 23 - Too much stress cannot be laid upon the importance of preventing the discharge of such refuse, and of sewage in its more restricted sense, into any stream or pond used, or likely to be used, as a source of water-supply.
Página 19 - Much depends, of course, upon the size of the stream into which the refuse is thrown. Thus, while into the Merrimack at Lowell, even during the summer, it would be necessary to throw more than 100 tons of solid matter daily in order to increase the amount in the water by one grain to the gallon, another and smaller stream might be hopelessly fouled by a single factory.
Página 18 - ... there brought forward. The principal causes which contribute to the apparent disappearance of the refuse received by the river are three, and these, in what I conceive to be the inverse order of their importance, are oxidation, deposition and dilution. Oxidation. — Although it is not practicable, in the case of a running stream like the Merrimack, to trace the progress of the destruction of the organic material by oxidation, yet there is no doubt that a certain amount is so destroyed. The presence...
Página 15 - It will be safe to infer, however, from the above results, that there is no river in the United Kingdom long enough to effect the destruction of sewage by oxidation.
Página 39 - As the contents of the water-hole, or well, are pumped out, they are immediately replenished from the surrounding disgusting mixture, and it is not, therefore, very surprising to be assured that such a well does not become dry, even in summer. Unfortunately, excrementitious liquids, especially after they have soaked through a few feet of porous soil, do not impair the palatability of water...

Información bibliográfica