For a given discharge, the efficiency of sedimentation tank can be increased by A. Increasing the depth of tank B. Decreasing the depth of tank C. Increasing the surface area of tank D. Decreasing the surface area of tank

The correct answer is: C. Increasing the surface area of tank.

The efficiency of a sedimentation tank is the fraction of suspended solids that are removed from the wastewater. The efficiency of a sedimentation tank can be increased by increasing the surface area of the tank. This is because the larger the surface area, the more particles have a chance to settle out of the water.

The depth of the tank does not affect the efficiency of the sedimentation tank. This is because the particles settle out of the water based on their density, not on the depth of the water.

The surface area of the tank is the most important factor in determining the efficiency of a sedimentation tank. The larger the surface area, the more particles have a chance to settle out of the water.