Elana Liskovich, Mahina Wang, Jill Freeman, Yiwen Ng
Abstract:
A floc blanket is a dense fluidized blanket of flocs that helps to reduce effluent turbidity in the sedimentation tank by trapping other flocs. The geometry of the sedimentation tank is crucial in determining the extent of floc resuspension by the jet and hence floc blanket formation. To improve tank bottom geometry, nine experiments were conducted, each testing a different tank bottom geometry. The experiments were run in a 1/2 inch wide tank to model a thin slice of the full scale sedimentation tank. The geometry that resulted in the least sludge accumulation and therefore best floc resuspension was two 60 degree inserts leading to a semicircular trench 10 cm in diameter. We also provided initial designs and calculations for a floc weir to maintain the height of the floc blanket. A preliminary experiment was also conducted to evaluate the feasibility of our initial floc weir design.
