In a wastewater or water treatment facility, the flow of clean water in a direction opposite (upward) to the normal flow of raw water through rapid sand filters in order to clean them.
Important Notice: Limited Web Access Dec 16 to 18, 2016
AIChE will undertake a routine upgrade of our digital infrastructure over the weekend of December 16-18, 2016. During this period access to certain areas of the website will be limited. Additional information will be forthcoming shortly.