2. Calculation of Removal Efficiency for a Primary Sedimentation Basin Determine the removal efficiency for a sedimentation basin with a critical overflow velocity of 2 m³/m²-h in treating a wastewater containing particles whose settling veloc- ities are distributed as given in the table below. Plot the particle histogram for the influ- ent and effluent wastewater. Settling velocity, m/h Number of particles per liter x 10-5 0.0-0.5 30 0.5-1.0 50 1.0-1.5 90 1.5-2.0 110 2.0-2.5 100 2.5-3.0 70 3.0-3.5 30 3.5-4.0 20 Total 500