Treatment
Spent backwash water is either discharged without treatment to a sanitary sewer system or is treated and recycled within the plant. Historically, backwash water was discharged directly to surface water supplies; however, direct discharge is now highly regulated through NPDES discharge permits and is often discouraged. Used backwash water contains high concentrations of particulate material. Typical treatment processes include coagulation, flocculation and sedimentation. High molecular weight synthetic organic polymers are sometimes added to facilitate the formation of settleable floc. Failure of a backwash treatment process and reintroduction of the resulting poor quality water into the main water purification plant flow stream can cause overall process upsets and result in the production of poor quality treated drinking water.
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Famous quotes containing the word treatment:
“The treatment of the incident of the assault upon the sailors of the Baltimore is so conciliatory and friendly that I am of the opinion that there is a good prospect that the differences growing out of that serious affair can now be adjusted upon terms satisfactory to this Government by the usual methods and without special powers from Congress.”
—Benjamin Harrison (1833–1901)
“Judge Ginsburg’s selection should be a model—chosen on merit and not ideology, despite some naysaying, with little advance publicity. Her treatment could begin to overturn a terrible precedent: that is, that the most terrifying sentence among the accomplished in America has become, “Honey—the White House is on the phone.””
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“James’s great gift, of course, was his ability to tell a plot in shimmering detail with such delicacy of treatment and such fine aloofness—that is, reluctance to engage in any direct grappling with what, in the play or story, had actually “taken place”Mthat his listeners often did not, in the end, know what had, to put it in another way, “gone on.””
—James Thurber (1894–1961)