P1. A biological tower has vertical-flow packing with a k20=0.0014(gpm/ft2)0.5,n=0.50, and A5 =36ft2/ft3. The tower is cylindrical, with a diameter of 32ft and depth of packing of 16ft. The primary effluent is 0.60mgd with 80mg/L of soluble BOD at a temperature of 14C. Direct recirculation is 400 gpm and the final clarifier is properly sized. (20 points) Calculate (a) the soluble BOD loading [lb/1000ft 3/ day] (b) the actual hydraulic loading that includes recycle [gpm/ ft2 ] (c) soluble effluent BOD using the Modified Velz equation. SoutSin={[R+1]exp([Qi(R+1)]nk20AsHT20)}R