迪肯assignment代写:水质条件

2017-07-09 22:31

显然，有一些水质条件是可以避免的，因为它们对水的使用有干扰。理想的情况下，例如，作为饮用水供给一个湖或水库水质量应该接近一个贫营养状态的可能，因为这将确保只有少量的预处理必须产生一个适合人类消费水。对于这样的水域，浮游植物含量（及其代谢产物）在水应尽可能低，为了促进这一目标。进一步的，如果水是从湖底的海域在夏季（通常是最大的藻类生长期），它不应该干扰从死亡的藻类细胞分解产生的物质。富营养化湖泊和水库也可作为饮用水供应。然而，在水适合人类饮用之前，必须进行广泛的预处理。有些水的使用可能根本不需要治疗，而不管现有的水质如何。例如消防用途和船舶运输商业货物。此外，在水资源极其有限的地区，几乎所有的水都可用于各种目的（不论是否治疗），不论其质量如何。因此，尽管人类可以使用具有一定水质的水，但实际上任何类型的用水都有理想的或最佳的水质。尽管它不是定量的，但在表3中提供了对这种用途的预期用水用途和最佳最小可接受营养状态的摘要。此外，根据国际经济合作与发展组织（1982）的国际富营养化研究（4），列举了几种不同营养条件对应的水质参数的值的例子。因此，可以确定给定用水的可接受或最佳水质。
迪肯assignment代写:水质条件
Obviously, there are water quality conditions to be avoided because of their interference with water uses. Ideally, for example, a lake or reservoir used as a drinking water supply should have water quality as close to an oligotrophy state as possible, since this would insure that only a minimum amount of pre-treatment would be necessary to yield a water suitable for human consumption. For such a waterbody, the content of phytoplankton (and their metabolic products) in the water should be as low as possible to facilitate this goal. Further, if the water is taken from the bottom waters of a lake during the summer (usually the period of maximum algal growth), it should be free of interferring substances resulting from decomposition of dead algal cells. Eutrophic lakes and reservoirs also could be used as a drinking water supply. However, extensive pre-treatment would be necessary before the water was suitable for human consumption.Some water uses may require no treatment at all, regardless of the existing water quality. Examples are fire-fighting purposes and the transport of commercial goods by ship. Further, in areas with extremely limited water resources, virtually all of the water may be used for various purposes (with or without treatment), regardless of its quality. Therefore, although humans can use water exhibiting a range of water quality, there is a desirable or optimal water quality for virtually any type of water usage. Though it is not quantitative in nature, a summary of intended water uses and the optimal versus minimally-acceptable trophic state for such uses is provided in Table 3. In addition, an example of the values of several commonly measured water quality parameters corresponding to different trophic conditions, based on the international eutrophication study of the Organization for Economic Cooperation and Development (1982), is provided in Table 4. Thus, it is possible to identify acceptable or optimal water quality for given water uses.

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