Question

. A wastewater treatment plant is to be designed for the 5-d sustained peak flowrate given an average daily flow of 13 MGD. Two aerated grit chambers in parallel will provide a total detention time of 4 minutes at peak flow. Determine: a) The volume of each chamber, in m3 . b) Chamber dimensions, in m, (length and width) if the design depth is 3.5 m and W:D is 1.2:1. Is the calculated L:W within the recommended range? c) Using the chamber width calculated in part b, determine the chamber length required to have a length-to-width ratio of 3:1. d) For the chamber volume calculated in part a and length from part c, what is the redesigned chamber depth and width-to-depth ratio? Is this ratio within the recommended range? e) Grit chamber detention time at Qavg, in min

Answer 1