Domestic Wastewater Treatment Mobilization Construction - AskTOP

EM 1110- 3-17211 May 84Weight Removed = 4 mgd x 300 mg/l x 8 .34 pounds/gallon x 0 .60= 6,000 pounds/dayTherefore 1,500 pounds are removed per 1 mgd flow .(6) Calculate sludge volume assuming a specific gravity of 1 .02,and a moisture content of 96 percent (4 percent solids),Sludge Volume =6,000 pounds/day1 .02(62 .4 pounds/cubic foot)(0 .04)2.,360 cubic feet/day (at 4 mgd)= 17,700 gpd(7) Sludge handling in this example consists of removing sludgefrom the settling tank sludge hopper using a telescoping sludge valvewhich discharges the sludge into a sump from which it is removed by asludge pump (or pumps) . Assume that the sludge will be wasted every 8hours and pumps for one-half hour to the digester .Sludge Sump Capacity =Daily Sludge VolumeNumber of Wasting Periods Per DayIncrease capacity 10percent= 2,360 cubic feet3= 787 cubic feet (= 5,900 gallons)to compensate for scum removal volumes :Sludge Pumping Capacity_Sludge and Scum Volume/Wasting Period30 minutes pumping/Wasting Period6,500 gallons = 217 gpm ; use 220 gpm30 minutesc . Pumps . Pump types used to convey sludge include the plunger,progressing-cavity, centrifugal, and torque-flow . The pump informationprovided ,is for guidance only and does not represent design criteria .For more information, refer to Pump Application Engineering .(1) Plunger . The advantages of plunger pumps may be listed asfollows :(a) Pulsating action tends to concentrate the sludge in thehoppers ahead of the pumps .