06-22 an industrial wastewater has a flow of 1.5 mgd and a tss of 25 mg/l which is made up of only one size of particles (0.04 mm). the specific gravity of these particles is 2.2 and the temperature of the flow is 20c. (a) determine the overflow rate (in gpd/ft2) needed to remove 75% of these particles by settling. (b) calculate the area (in ft2) of the settling tank needed for this flow. (c) calculate the daily mass (in lb) of dry solids that must be disposed of from this process. assume the volume of sludge is negligibly small compared to the water flow. 2945 gpd/ft2, 509 ft2, 235 lb/d