Question:
Sedimentation as a method of water purification results in?

A an increase in the bacterial countB a decrease in the amount of organic matterC an increase in the amount of hydrogenD a more rapid water flowE the destruction of vitamins

Answer: B. As the matter settles in the bottom of the basin.

"There are a wide range of techniques that can be used to remove the fine solids, micro-organisms and some dissolved inorganic and organic materials. The choice of method will depend on the quality of the water being treated, the cost of the treatment process and the quality standards expected of the processed water" - wikipedia

http://en.wikipedia.org/wiki/water_purif... under secondary purfication methods.