Home Work
1. Each day 3780 m3 of wastewater is
treated at a municipal wastewater
treatment plant. The influent contains
220 mg/L of suspended solids. The
clarified water has a suspended solids
concentration of 5mg/L. Determine the
mass of sludge produced daily from the
clarifier and write down the mass
balance of the clarifier.
Home Work
2. A wastewater treatment plant with an output
of 38400m3/day discharges the liquid effluent
with a BOD of 20mg/L into a river. If the BOD
of the river upstream of the discharge point is
0.2mg/l, at a minimum flow of 20m3/s,
compare the BOD of the river downstream of
the discharge, assuming complete mixing.
• Answer = 0.63mg/L
HOME WORK
3. A slurry containing 20 percent by weight of
limestone (CaCO3) is processes to separate
pure dry limestone from water. If feed rate is
2000kg/h, how much CaCO3 is produced per
hour?