Technology
Although sedimentation might occur in tanks of other shapes, removal of accumulated solids is easiest with conveyor belts in rectangular tanks or with scrapers rotating around the central axis of circular tanks. Mechanical solids removal devices move as slowly as practical to minimize resuspension of settled solids. Tanks are sized to give water an optimal residence time within the tank. Economy favors using small tanks; but if flow rate through the tank is too high, most particles will not have sufficient time to settle, and will be carried with the treated water. Considerable attention is focused on reducing water inlet and outlet velocities to minimize turbulence and promote effective settling throughout available tank volume. Baffles are used to prevent fluid velocities at the tank entrance from extending into the tank; and overflow weirs are used to uniformly distribute flow from liquid leaving the tank over a wide area of the surface to minimize resuspension of settling particles.
Read more about this topic: Sedimentation (water Treatment)
Famous quotes containing the word technology:
“Our technology forces us to live mythically, but we continue to think fragmentarily, and on single, separate planes.”
—Marshall McLuhan (19111980)
“One can prove or refute anything at all with words. Soon people will perfect language technology to such an extent that theyll be proving with mathematical precision that twice two is seven.”
—Anton Pavlovich Chekhov (18601904)
“If we had a reliable way to label our toys good and bad, it would be easy to regulate technology wisely. But we can rarely see far enough ahead to know which road leads to damnation. Whoever concerns himself with big technology, either to push it forward or to stop it, is gambling in human lives.”
—Freeman Dyson (b. 1923)